Do you hear that buzz? It's a mosquito!
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In this episode, we're tackling all the mosquito questions that have been bugging our listeners. Why do they bite? Why do the bites itch? Is scratching them a good idea? Why do some people seem to be more delicious to mosquitoes? How can we keep them away from us? And are mosquitoes good for the world? The Hoax Hunters make an appearance plus the Moment of Um answers the question, "What is a solar flare?"
Audio Transcript
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AYAN: You're listening to Brains On where we're serious about being curious.
SPEAKER 1: Brains On is supported in part by a grant from the National Science Foundation.
[DOOR OPENS]
MOLLY BLOOM: OK, Ayan. We're going to get started with the taping in just a sec.
AYAN: OK. Awesome. Where do I sit?
[BUZZING]
MOLLY BLOOM: Shh. Do you hear that?
AYAN: Hear what?
MOLLY BLOOM: There it is.
AYAN: I don't hear anything. Oh, wait. I hear it now.
MOLLY BLOOM: It's weird. Like, one second it's there, and then it's not. OK. We got to figure this out before we start taping. Menaka!
[DOOR OPENS]
MENAKA WILHELM: Yeah, Molly?
MOLLY BLOOM: Do you hear that noise?
MENAKA WILHELM: Uh, no.
MOLLY BLOOM: It sounds a little bit like this. [BUZZES]
Actually, I think it's like a little higher pitched like this, like-- [HIGH-PITCHED BUZZING]
AYAN: Molly, I respectfully disagree. It's definitely like a-- [BUZZES]
MOLLY BLOOM: No, no. It's like this, Menaka. Trust me. [HIGH-PITCHED BUZZING]
MENAKA WILHELM: Hmm.
AYAN: Menaka, my younger ears are far more sensitive. It's like this. [BUZZES]
MOLLY BLOOM: No, no. It's like this. [HIGH-PITCHED BUZZING]
AYAN: No, no. It's like this. [BUZZES]
[BOTH BUZZING]
MENAKA WILHELM: It seems like you guys have to work this out. I'll leave this to you all and, uh, see myself out.
MOLLY BLOOM: Wait! I heard it.
AYAN: Oh, me too. I think it's over there.
MOLLY BLOOM: I think it's underneath-- it's underneath your chair?
MENAKA WILHELM: Have a good taping. Bye!
AYAN: --underneath my chair. Maybe, is it under yours?
MOLLY BLOOM: Oh, wait. No, I think it's up by the ceiling?
[CHATTERING CONTINUES]
[THEME MUSIC]
You're listening to Brains On. I'm Molly Bloom. And my co-host today is Ayan from Chicago, Illinois. Hi, Ayan.
AYAN: Hi, Molly. And-- [BUZZES]. [GASP] There's that noise again. [GASP] Oh! There's the source. It's a mosquito.
MOLLY BLOOM: Oh, nice work, Ayan. OK, I'll just swat this thing and get on with the show.
MOSQUITO: Wait! Don't swat!
MOLLY BLOOM: What the what? A talking mosquito?
MOSQUITO: Hey, when you hang around in a recording studio long enough, you pick up a few things.
MOLLY BLOOM: Huh.
MOSQUITO: I'm a huge fan of podcasts. I've been trying to work my way in here for days.
MOLLY BLOOM: Welcome, I guess. Hey, as long as you're here, maybe you could help us answer this question that was sent in from Provo, Utah.
COLIN: Hello. I am Colin. My question is, how do mosquitoes suck out your blood?
MOSQUITO: Great question, Colin.
MOLLY BLOOM: Um, that's usually my line.
MOSQUITO: Well, take a look at these mouthparts here.
MOLLY BLOOM: You'll have to describe them. This is a podcast.
MOSQUITO: Oh yeah! I'm a mosquito, and I'm here to show you my mouthparts.
MOLLY BLOOM: Tell, don't show.
MOSQUITO: Oh yeah. There are six different needle-looking structures here that help me get my blood meal. These two, these ones that look like little saws, they're for piercing your skin. And these two, these ones hold the skin open so that I can stick this other needle into one of your blood vessels. That's the one that sucks up the blood. And then this last one injects some of my saliva into your blood.
AYAN: Ew. Why? That's just-- that's just gross.
MOSQUITO: It's not gross. It's useful! My spit does all sorts of amazing things to your blood chemistry. It keeps your blood from clotting and also opens your blood vessels wider. This helps me eat faster so I can get out there before you, um, squish me.
AYAN: I see. Well, here's a thought. How about maybe just not biting us? Your chances of getting squashed would go way down.
MOSQUITO: Yeah, about that. See, I kind of need the blood actually. Only female mosquitoes bite because we need the protein and blood to make eggs and eventually little baby mosquitoes. They're so cute. They kind of look like little spiky dandelions.
MOLLY BLOOM: Sounds adorable?
MOSQUITO: You know, one has ever taken the time to chat with me. Thank you so much, Molly, for having me here today.
MOLLY BLOOM: Well, it's actually worked out really well. High five, mosquito!
[HIGH FIVES]
Oops.
SINGERS: Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba. Brains On.
MOLLY BLOOM: Wow. So apparently, mosquitoes bite us with mouthparts that are almost like a six-part Swiss Army knife. So Ayan, do you get mosquito bites?
AYAN: Uh, I get lots of mosquito bites, especially in the summer when I'm playing with my friends outside, like soccer, baseball. Even when we're just running, the mosquitoes, they just bite us and bite us. And it's really annoying, and itches a lot.
MOLLY BLOOM: So do you have any tips for, like, how to make them stop itching?
AYAN: I would recommend using bug spray. It just really works really well.
MOLLY BLOOM: Good advice. And what about once you get that mosquito bite? How do you make it stop itching? Or does it just itch and itch and itch?
AYAN: It just itches and itches and itches. You have to wait for it to go down before, like, the bite actually goes away.
MOLLY BLOOM: Yeah, that can take a while. That brings us to something that you wondered about Ayan.
AYAN: Why do mosquito bites swell up and itch?
MOLLY BLOOM: Now that our mosquito guest is, um, no longer with us, we have a human mosquito expert who's agreed to help us.
LYRIC BARTHOLOMAY: My name is Lyric Bartholomay.
MOLLY BLOOM: She's a medical entomologist from the University of Wisconsin-Madison. Remember that saliva we heard about earlier? That's the key to the itch.
LYRIC BARTHOLOMAY: There's actually a whole series of different proteins inside mosquito spit. The proteins in the saliva are causing your immune system to just go wild. Your body's recognizing that there's something there that wasn't supposed to be there.
MOLLY BLOOM: So your immune system responds, and you get an inflammatory response, which is that familiar itchy, swelling redness.
LYRIC BARTHOLOMAY: She doesn't really mean to do it. [CHUCKLES] But you get an itchy bite left behind.
AYAN: And next comes scratching.
MOLLY BLOOM: Another very popular topic for questions.
CHLOE: Hi. My name is Chloe. I live in Coeur d'Alene, Idaho. My question is, why does scratching an itch make you satisfied? I started thinking about this one day because I had a rea-- had an itch. So I started scratching it. It felt really good. But then I had to scratch it again to make it feel satisfied.
MOLLY BLOOM: The thing is, scratching mosquito bites feels so good.
AYAN: But then your itchiness usually comes back to you.
MOLLY BLOOM: So what gives?
AYAN: Well, you feel itching and scratching with cells in your skin called neurons.
MOLLY BLOOM: Neurons sense what's going on in your skin, and they tell your brain about it.
AYAN: But the neurons that feel itching are different from the neurons that feels a scratching.
MOLLY BLOOM: So there's a cycle of itching and scratching. It's almost like a dramatic phone call between two kinds of neurons.
AYAN: Sonali Mali will tell us about it. She studies itch at UC, Berkeley.
SONALI MALI: Yeah, so your itch neurons can tell that there is a mosquito and that there is some chemical that the mosquito's put into your skin.
[TAPPING SOUNDS]
ITCH NEURON: Ah! I'm an itch neuron, and I feel an itch. And I've got to get that to the brain.
[PHONE RINGS]
Ah! Pick up, pick up, pick up, pick up, pick up.
BRAIN: Hi, Itch Neuron. What do you need? [CHUCKLES]
SONALI MALI: And they tell your brain, you're going to experience an itchiness in this spot right here, say, it's on your arm.
ITCH NEURON: Brain, it's your arm, there's an itch. You've got to scratch it.
BRAIN: OK, you got it. I'll move the fingers and start scratching.
[SCRATCHING]
Do we need to keep talking?
ITCH NEURON: Yes. Stay on the line! It's still itchy! Oh, it's still itchy.
SONALI MALI: So another set of neurons that respond to scratching, and these are pain neurons, will get activated. And they'll start outcompeting the itch signal to your brain. And so you don't really feel the itchiness at that moment.
PAIN NEURON: Uh, scratching? I'm a pain neuron, and I feel that scratch as pain. Brain, pick up my call.
[PHONE RINGS]
BRAIN: Sorry, Itch. Another call is coming in. Hi.
PAIN NEURON: Listen.
BRAIN: Hey, Neuron.
PAIN NEURON: Your arm is in pain.
BRAIN: Huh. So we're kind of going from itch to ouch. OK?
[SCRATCHING]
ITCH NEURON: Uh, Brain? I still have itch messages. Hello? Hello? Why would you choose pain over an itch?
SONALI MALI: Itch is also a really unpleasant sensation, just as we think pain is an unpleasant sensation. And so by stopping the itch, your brain is feeling really rewarded because when you're already feeling itch, that pain actually feels good.
BRAIN: Compared to that terrible itch, the pain of scratching is a dream.
PAIN NEURON: Here that, itch? Brain likes me better than you.
SONALI MALI: But the chemical or whatever is making you itchy isn't actually going away. And after a while, the pain sensation will stop overriding the itch sensation, and you'll continue to experience it.
ITCH NEURON: Like it or not, that's when I come back, baby!
BRAIN: Ugh, here we go again.
SONALI MALI: While scratching feels good temporarily, in the end, it can actually make things much worse.
BRAIN: Scratching irritates your skin, and your nails turn a bug bite into a wound. Don't do that.
SONALI MALI: But also, something else that sometimes makes it feel better is some kind of like hot or cold applied to that area.
BRAIN: That's because there are other neurons that sense temperature besides pain and itch neurons. So if you rub an ice cube on an itchy bug bite, a temperature neuron will tell me about coldness, and I won't have to hear about itch or pain. Please try that instead of scratching.
MOLLY BLOOM: Eventually, your immune system will get rid of all the itchy proteins in a mosquito bite, and your itch will go away.
AYAN: In the meantime, try not to scratch.
ROBOTIC VOICE: Brain, Brains, Brains On.
MOLLY BLOOM: Here's something even better than scratching an itch. It's the--
CHILD: (WHISPERS) Mystery sound.
MOLLY BLOOM: Here it is.
[MYSTERY SOUND]
OK. What are your thoughts.
AYAN: Well, firstly, I think it's like a video game, like Space Invaders maybe.
MOLLY BLOOM: Kind of sounds like laser-y?
AYAN: Yeah, like an arcade maybe.
MOLLY BLOOM: Good thinking. We'll hear it again and give you another chance to guess a little bit later in the show.
AYAN: All righty.
[MUSIC PLAYING]
MOLLY BLOOM: We've got an episode all about teeth coming up.
AYAN: And we want to hear from you.
MOLLY BLOOM: If you were the tooth fairy, what would you leave for kids who have lost teeth and why? So
AYAN: Ayan, what would you leave as a present for lost teeth? I'll probably give them cookies or something because sometimes-- you know, they're really good, so I would probably choose cookies.
MOLLY BLOOM: Would you put the cookie under the pillow? Or would that get too messy?
AYAN: I feel like it would be too messy. I would only put it under the pillow if they're in like a Ziploc. But even then, they might get like-- I don't know, kind of like cracked or something. So if they have a nightstand or something, I would put them there with a little letter that says, from the tooth fairy.
MOLLY BLOOM: I love that idea. Well, listeners, send us your answers too at brainson.org/contact. And while you're there, you can send us your mystery sounds, drawings, and questions.
AYAN: Like this one.
GRAHAM: Hi. My name is Graham. My question is, what is a solar flare?
MOLLY BLOOM: We'll answer that question during our Moment of Um, and we'll read the latest group of listeners to be added to the Brains Honor Roll, all at the end of the show.
AYAN: So keep listening.
MOLLY BLOOM: You're listening to Brains On from American Public Media. I'm Molly.
AYAN: I'm Ayan.
MARC SANCHEZ: I'm Marc.
SANDEN TOTTEN: And I'm Sanden.
MARC SANCHEZ: And we are--
MARC AND SANDEN: The Hoax Hunters.
SANDEN TOTTEN: Yeah.
MARC SANCHEZ: Can I get some music?
[MUSIC PLAYING]
MARC AND SANDEN: (SINGING) We like myths, but we hate getting tricked. Yeah! We like myths, but we hate getting tricked. Yeah! All right! We like myths, but we hate getting tricked. We hate getting tricked. No, we don't like it.
[MUSIC PLAYING]
SANDEN TOTTEN: Because we love myths, and we hate getting tricked.
MARC SANCHEZ: A hoax is when somebody tricks you into believing something that isn't true.
SANDEN TOTTEN: Today's hoax is all about a fart.
[FART]
MARC SANCHEZ: And it all started in December 2019 when various papers reported about a man from Uganda whose farts were so powerful, they killed mosquitoes.
SANDEN TOTTEN: The British paper, The Sun, published an article all about the man Joe Rwamirama, reporting that bug spray companies hired him to study his glorious gas. According to the article, his farts were so strong, they covered a six-mile radius.
MARC SANCHEZ: Now that is one tremendous toot. Maybe too tremendous.
SANDEN TOTTEN: You're right to be suspicious. Turns out, his farts weren't the only thing that smelled funny. The article was completely made up.
[ELECTRIC GUITAR]
MAN: Get hoaxed.
SANDEN TOTTEN: The original article came from a satirical news website. That is to say, it was all a joke.
MARC SANCHEZ: But other outlets didn't catch that part, so they thought it was real. And they retold the story without any fact checking.
SANDEN TOTTEN: Big mistake.
MARC SANCHEZ: Huge! And before you knew it, the story had spread like a fart next to a fan
MAN: Everyone got hoaxed.
[EXCLAIMS]
SANDEN TOTTEN: This isn't the first bogus story about bug repellents. Turns out, there's a lot of bad information out there.
MARC SANCHEZ: Yeah, like rub a dryer sheet on your arms, eat garlic, or pour mouthwash all over your porch?
SANDEN TOTTEN: But those claims don't have much scientific evidence to back them up. However, there are lots of insect repellents that are backed by research and testing. Yeah.
[MUSIC PLAYING]
MARC SANCHEZ: Chris Potter has done a lot of research himself. He's a professor of neuroscience at Johns Hopkins University.
CHRIS POTTER: If you go to the drugstore, the most commonly used one is called DEET. It stands for N,N-diethyl-3-methyl-amide. But that's quite a mouthful, so it's just been abbreviated as DEET. That's like the gold standard for insect repellents.
SANDEN TOTTEN: Chris says DEET works in a couple of different ways. First, it changes the way you smell to a mosquito.
CHRIS POTTER: So when you put DEET on your skin, it prevents other odors on your skin from being volatiles, meaning they don't come off your skin as they would normally do. And so what that does is it kind of keeps your odors to yourself. So the first thing that DEET can do is it essentially changes the way you smell. You just don't smell like a human anymore.
MARC SANCHEZ: So when a mosquito is trying to find you, it just can't.
CHRIS POTTER: The second thing that can do is that it can activate neurons on the antenna, which is essentially the nose of the mosquito. And when it activates these neurons in the mosquito's nose, it smells bad to the mosquito.
SANDEN TOTTEN: Smell you later, skeeters. [MOCKING]
CHRIS POTTER: And the third thing that DEET can do is that when an insect like a mosquito lands on your skin-- there are neurons in its feet. And so when they land on us, they can actually use this for tasting. So they're essentially tasting us when they land on us. And if you have DEET on your skin, this tastes really bad to a mosquito. So as soon as it lands on your skin, and it touches DEET, it tastes bad, and it'll jump away.
MARC AND SANDEN: Tuh-DEET!
MARC SANCHEZ: But I'm going to be honest, these mosquitoes aren't really bothering me.
SANDEN TOTTEN: What? Ugh, I'm itching like crazy over here. Ooh. Why is it that Marc is fine and dandy, but I'm out here getting eaten alive? Ugh.
CHRIS POTTER: Everybody smells good to a mosquito, but some people smell better than others. And so the odor we give off, it's a very complex odor, like a bouquet, I guess. There's bacteria and other things that are on your skin that take your odors, take your chemicals and turn it into odors. And so it's a combination of all those things that make you smell the way you do. Some people are giving off certain chemicals that allow them to smell better to mosquitoes. Other people actually have some chemicals on their skin that don't smell quite as nice to a mosquito.
MARC SANCHEZ: I guess I lucked out with these genius genes. Shout out to Mom and Dad! Woot woot!
CHRIS POTTER: One thing to realize is that sometimes what happens is that people just don't react to the mosquito bites. And so they might just be just as attractive to mosquitoes and being bitten by mosquitoes, but they just don't realize it because they just don't react to the bites.
SANDEN TOTTEN: Well, even if I get all bit up, at least mosquitoes appreciate my smell. There's notes of buttered popcorn, time machine dust, and just a hint of vanilla.
[SNIFFING]
MARC SANCHEZ: Mm, that's not bad.
SANDEN TOTTEN: Thanks, Chris, for helping out.
CHRIS POTTER: Yeah, no problem. Thanks for calling.
[MUSIC PLAYING]
MARC SANCHEZ: That's all for Hoax Hunters today. Remember to check your sources, folks.
SANDEN TOTTEN: And always look for evidence that backs up a big claim or a lofty headline.
MARC SANCHEZ: Because you definitely don't want to get hoaxed.
MARC AND SANDEN: Hoax Hunters, out!
MOLLY BLOOM: OK. Ayan, we still need your ears to point to the true identity of this mystery sound. Let's hear it again.
[MYSTERY SOUND]
The last time, you were thinking something video game related. Do you have any new thoughts?
AYAN: Maybe like laser tag.
MOLLY BLOOM: Ooh, you play laser tag?
AYAN: Well, with my friends. For birthday parties. we play laser tag lots of times. I've played it a lot, so.
MOLLY BLOOM: Can you describe what laser tag is for someone who might not know?
AYAN: OK. So for laser tag, you pretty much have these vests, kind of with like sensors on them. And pretty much, you have kind of like a laser gun, I would say. And it used, like, a red light. And if you hit the sensor, they're out. And they have to go to a recharging station so they can get back in. And when you get hit, it makes an odd noise, kind of like the one it just showed in the mystery sound.
MOLLY BLOOM: You ready to hear the answer?
AYAN: Yes.
MOLLY BLOOM: Here it is.
BRAZEN: My name is Brazen from Seattle, Washington. That was the sound of me dropping a rock into a six-inch diameter steel pipe that is an abandoned well on our rural property in Bremerton, Washington. We think the old well is 250 feet deep. My dad is so excited that there is water at the bottom.
AYAN: That is oddly specific, but OK.
MOLLY BLOOM: Yes, that is very specific. But yeah, that sort of laser-like noise is the sound of the rock echoing--
AYAN: Like going down the pipe.
MOLLY BLOOM: Exactly. And it's really deep at the ground, so it just kind of keeps going and going and going. And then it lands in the water at the bottom.
[FADING LASER SOUNDS]
AYAN: Mosquitoes are tiny creatures, but they have a big impact on humans.
MOLLY BLOOM: Here's Lyric Bartholomay again.
LYRIC BARTHOLOMAY: The mosquito that transmits malaria parasites in Africa is the most dangerous animal on the planet, by any measure, because of the number of people that die after having been bitten by those mosquitoes.
AYAN: So that brings us to this question from Brian.
BRIAN: My question is, do mosquitoes have a purpose to be on the Earth? They go around annoying everybody. They suck your blood. So what are they meant for?
MOLLY BLOOM: Lyric says that even though mosquitoes are a nuisance and potentially dangerous, they play an important role in the ecosystem.
LYRIC BARTHOLOMAY: The environment benefits from mosquitoes being there because mosquitoes feed all kinds of animals. You can find the mosquitoes, lots of mosquitoes in the bellies of ducks and frogs and all kinds of different animals. And so they're a really essential part of the food chain in places where we do a really good job of controlling mosquitoes and just take all of them out of the environment.
It can have an impact on things like bird reproduction. So a bird lays an egg, and she needs proper nourishment in order to lay healthy eggs too. And so if she doesn't have all the mosquitoes to feed on, she might have sort of brittle eggshells. Now I've told you that, but there's more than 3,000 kinds of mosquito. For example, in the state of Iowa with 55 different kinds of mosquitoes that we see, maybe about five of them are important in terms of disease transmission.
MOLLY BLOOM: Lyric says that instead of getting rid of all mosquitoes, scientists are working on ways to control the small number of mosquito species that do spread disease and pathogens.
LYRIC BARTHOLOMAY: Yeah. There are all kinds of really beautiful and creative ways that people are coming up with.
MOLLY BLOOM: One strategy involves infecting mosquitoes with a bacteria called Wolbachia. This bacteria is a natural one already living in some mosquitoes, just like all the bacteria we have living in our guts.
LYRIC BARTHOLOMAY: What we've learned is that mosquitoes that are infected with Wolbachia are also not readily infected with other things. So it's a really powerful potential tool.
MOLLY BLOOM: So mosquitoes with this Wolbachia shouldn't be able to pick up and spread other diseases, making them a pest but not deadly.
LYRIC BARTHOLOMAY: Sure they're dangerous animals, but I think we should appreciate how important they are. How can we appreciate the mosquitoes and understand their diversity and how they fit in an ecosystem but also try and control the really dangerous ones for the benefit of people's health.
[THEME MUSIC]
MOLLY BLOOM: Female mosquitoes use six different mouthparts to bite you.
AYAN: It's the mosquito spit that makes your bug bite itch.
MOLLY BLOOM: Scratching a bug bite feels good because it gives your brain a break from an itch.
AYAN: But try not to scratch. The itch will stop when your immune system cleans up all of the mosquito spit.
MOLLY BLOOM: All humans smell good to mosquitoes, unless we wear repellents like DEET. Then they can't smell us at all.
AYAN: Some mosquitoes spread dangerous diseases, but others make great snacks for birds and spiders.
MOLLY BLOOM: That's it for this episode of Brains On.
AYAN: Brains On is produced by Menaka Wilhelm, Sanden Totten, Marc Sanchez, and Molly Bloom.
MOLLY BLOOM: We had production help from [INAUDIBLE] Georgie, Ruby Guthrie, and Christina Lopez and engineering help from Veronica Rodriguez, Eric Romani, and Sean [INAUDIBLE]. Special thanks to Jennifer and Josh Ellman, Christina Lopez, Rosie duPont, and John Sklaroff.
AYAN: Brains On is a non-profit public radio program.
MOLLY BLOOM: You can support the show at brainson.org/fans. There you can find links to donate, or join our free fan club, or check out our Brains On merch.
AYAN: We now have brains on shirts, baseball hats, and face masks.
MOLLY BLOOM: And you can buy the Brains On book there too. That's brainson.org/fans.
AYAN: And now, before we go, it's time for the Moment of Um.
[CHORUS OF UMS]
GRAHAM: What is a solar flare?
MOLLY BLOOM: Here with the answer is Dr. Nicola Fox. She's the director of NASA's heliophysics division. Heliophysics is the science of understanding the sun.
NICOLA FOX: Oh, solar flares are wonderful. So they're some of the most beautiful things that you see happening on our sun's the surface. So if you look at the sun, invisible light-- obviously, you don't look at the sun directly, but if you use a filter, or you look at images on the web, and you look at a sun in visible light, you'll see it's kind of a uniform sphere. But it may have a few little dark splotches on the sun, and they are sun spots. And they are actually associated with very intense active regions on the sun.
From time to time, these active regions get sort of so much energy kind of pent up inside that active region that they have to explode and sort of release the energy out away from the active region. So that it's just like this big explosion of light and heat and also radiation that comes out with it. And they can actually interfere with us here at Earth.
They can interact with our Earth's magnetic field, and they can cause very big space weather events here at Earth-- things like beautiful Aurora that you can see in the sky, also issues with power grids, problems with spacecraft, with GPS navigation. And so that's one of the reasons that we really, really want to understand our star so well so that we can predict space weather, and we can better protect life and society here on Earth.
[MUSIC PLAYING]
[CHORUS OF UMS]
MOLLY BLOOM: Here's a list of names that shines as bright as the sun. It's the Brains Honor Roll. These are the incredible listeners who share their questions, ideas, mystery sounds, drawings, and high fives with us.
[LISTING HONOR ROLL]
[MUSIC PLAYING]
MOLLY BLOOM: We'll be back soon with more answers to your questions.
AYAN: Thanks for listening!
SPEAKER 1: Brains On is supported in part by a grant from the National Science Foundation.
[DOOR OPENS]
MOLLY BLOOM: OK, Ayan. We're going to get started with the taping in just a sec.
AYAN: OK. Awesome. Where do I sit?
[BUZZING]
MOLLY BLOOM: Shh. Do you hear that?
AYAN: Hear what?
MOLLY BLOOM: There it is.
AYAN: I don't hear anything. Oh, wait. I hear it now.
MOLLY BLOOM: It's weird. Like, one second it's there, and then it's not. OK. We got to figure this out before we start taping. Menaka!
[DOOR OPENS]
MENAKA WILHELM: Yeah, Molly?
MOLLY BLOOM: Do you hear that noise?
MENAKA WILHELM: Uh, no.
MOLLY BLOOM: It sounds a little bit like this. [BUZZES]
Actually, I think it's like a little higher pitched like this, like-- [HIGH-PITCHED BUZZING]
AYAN: Molly, I respectfully disagree. It's definitely like a-- [BUZZES]
MOLLY BLOOM: No, no. It's like this, Menaka. Trust me. [HIGH-PITCHED BUZZING]
MENAKA WILHELM: Hmm.
AYAN: Menaka, my younger ears are far more sensitive. It's like this. [BUZZES]
MOLLY BLOOM: No, no. It's like this. [HIGH-PITCHED BUZZING]
AYAN: No, no. It's like this. [BUZZES]
[BOTH BUZZING]
MENAKA WILHELM: It seems like you guys have to work this out. I'll leave this to you all and, uh, see myself out.
MOLLY BLOOM: Wait! I heard it.
AYAN: Oh, me too. I think it's over there.
MOLLY BLOOM: I think it's underneath-- it's underneath your chair?
MENAKA WILHELM: Have a good taping. Bye!
AYAN: --underneath my chair. Maybe, is it under yours?
MOLLY BLOOM: Oh, wait. No, I think it's up by the ceiling?
[CHATTERING CONTINUES]
[THEME MUSIC]
You're listening to Brains On. I'm Molly Bloom. And my co-host today is Ayan from Chicago, Illinois. Hi, Ayan.
AYAN: Hi, Molly. And-- [BUZZES]. [GASP] There's that noise again. [GASP] Oh! There's the source. It's a mosquito.
MOLLY BLOOM: Oh, nice work, Ayan. OK, I'll just swat this thing and get on with the show.
MOSQUITO: Wait! Don't swat!
MOLLY BLOOM: What the what? A talking mosquito?
MOSQUITO: Hey, when you hang around in a recording studio long enough, you pick up a few things.
MOLLY BLOOM: Huh.
MOSQUITO: I'm a huge fan of podcasts. I've been trying to work my way in here for days.
MOLLY BLOOM: Welcome, I guess. Hey, as long as you're here, maybe you could help us answer this question that was sent in from Provo, Utah.
COLIN: Hello. I am Colin. My question is, how do mosquitoes suck out your blood?
MOSQUITO: Great question, Colin.
MOLLY BLOOM: Um, that's usually my line.
MOSQUITO: Well, take a look at these mouthparts here.
MOLLY BLOOM: You'll have to describe them. This is a podcast.
MOSQUITO: Oh yeah! I'm a mosquito, and I'm here to show you my mouthparts.
MOLLY BLOOM: Tell, don't show.
MOSQUITO: Oh yeah. There are six different needle-looking structures here that help me get my blood meal. These two, these ones that look like little saws, they're for piercing your skin. And these two, these ones hold the skin open so that I can stick this other needle into one of your blood vessels. That's the one that sucks up the blood. And then this last one injects some of my saliva into your blood.
AYAN: Ew. Why? That's just-- that's just gross.
MOSQUITO: It's not gross. It's useful! My spit does all sorts of amazing things to your blood chemistry. It keeps your blood from clotting and also opens your blood vessels wider. This helps me eat faster so I can get out there before you, um, squish me.
AYAN: I see. Well, here's a thought. How about maybe just not biting us? Your chances of getting squashed would go way down.
MOSQUITO: Yeah, about that. See, I kind of need the blood actually. Only female mosquitoes bite because we need the protein and blood to make eggs and eventually little baby mosquitoes. They're so cute. They kind of look like little spiky dandelions.
MOLLY BLOOM: Sounds adorable?
MOSQUITO: You know, one has ever taken the time to chat with me. Thank you so much, Molly, for having me here today.
MOLLY BLOOM: Well, it's actually worked out really well. High five, mosquito!
[HIGH FIVES]
Oops.
SINGERS: Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba. Brains On.
MOLLY BLOOM: Wow. So apparently, mosquitoes bite us with mouthparts that are almost like a six-part Swiss Army knife. So Ayan, do you get mosquito bites?
AYAN: Uh, I get lots of mosquito bites, especially in the summer when I'm playing with my friends outside, like soccer, baseball. Even when we're just running, the mosquitoes, they just bite us and bite us. And it's really annoying, and itches a lot.
MOLLY BLOOM: So do you have any tips for, like, how to make them stop itching?
AYAN: I would recommend using bug spray. It just really works really well.
MOLLY BLOOM: Good advice. And what about once you get that mosquito bite? How do you make it stop itching? Or does it just itch and itch and itch?
AYAN: It just itches and itches and itches. You have to wait for it to go down before, like, the bite actually goes away.
MOLLY BLOOM: Yeah, that can take a while. That brings us to something that you wondered about Ayan.
AYAN: Why do mosquito bites swell up and itch?
MOLLY BLOOM: Now that our mosquito guest is, um, no longer with us, we have a human mosquito expert who's agreed to help us.
LYRIC BARTHOLOMAY: My name is Lyric Bartholomay.
MOLLY BLOOM: She's a medical entomologist from the University of Wisconsin-Madison. Remember that saliva we heard about earlier? That's the key to the itch.
LYRIC BARTHOLOMAY: There's actually a whole series of different proteins inside mosquito spit. The proteins in the saliva are causing your immune system to just go wild. Your body's recognizing that there's something there that wasn't supposed to be there.
MOLLY BLOOM: So your immune system responds, and you get an inflammatory response, which is that familiar itchy, swelling redness.
LYRIC BARTHOLOMAY: She doesn't really mean to do it. [CHUCKLES] But you get an itchy bite left behind.
AYAN: And next comes scratching.
MOLLY BLOOM: Another very popular topic for questions.
CHLOE: Hi. My name is Chloe. I live in Coeur d'Alene, Idaho. My question is, why does scratching an itch make you satisfied? I started thinking about this one day because I had a rea-- had an itch. So I started scratching it. It felt really good. But then I had to scratch it again to make it feel satisfied.
MOLLY BLOOM: The thing is, scratching mosquito bites feels so good.
AYAN: But then your itchiness usually comes back to you.
MOLLY BLOOM: So what gives?
AYAN: Well, you feel itching and scratching with cells in your skin called neurons.
MOLLY BLOOM: Neurons sense what's going on in your skin, and they tell your brain about it.
AYAN: But the neurons that feel itching are different from the neurons that feels a scratching.
MOLLY BLOOM: So there's a cycle of itching and scratching. It's almost like a dramatic phone call between two kinds of neurons.
AYAN: Sonali Mali will tell us about it. She studies itch at UC, Berkeley.
SONALI MALI: Yeah, so your itch neurons can tell that there is a mosquito and that there is some chemical that the mosquito's put into your skin.
[TAPPING SOUNDS]
ITCH NEURON: Ah! I'm an itch neuron, and I feel an itch. And I've got to get that to the brain.
[PHONE RINGS]
Ah! Pick up, pick up, pick up, pick up, pick up.
BRAIN: Hi, Itch Neuron. What do you need? [CHUCKLES]
SONALI MALI: And they tell your brain, you're going to experience an itchiness in this spot right here, say, it's on your arm.
ITCH NEURON: Brain, it's your arm, there's an itch. You've got to scratch it.
BRAIN: OK, you got it. I'll move the fingers and start scratching.
[SCRATCHING]
Do we need to keep talking?
ITCH NEURON: Yes. Stay on the line! It's still itchy! Oh, it's still itchy.
SONALI MALI: So another set of neurons that respond to scratching, and these are pain neurons, will get activated. And they'll start outcompeting the itch signal to your brain. And so you don't really feel the itchiness at that moment.
PAIN NEURON: Uh, scratching? I'm a pain neuron, and I feel that scratch as pain. Brain, pick up my call.
[PHONE RINGS]
BRAIN: Sorry, Itch. Another call is coming in. Hi.
PAIN NEURON: Listen.
BRAIN: Hey, Neuron.
PAIN NEURON: Your arm is in pain.
BRAIN: Huh. So we're kind of going from itch to ouch. OK?
[SCRATCHING]
ITCH NEURON: Uh, Brain? I still have itch messages. Hello? Hello? Why would you choose pain over an itch?
SONALI MALI: Itch is also a really unpleasant sensation, just as we think pain is an unpleasant sensation. And so by stopping the itch, your brain is feeling really rewarded because when you're already feeling itch, that pain actually feels good.
BRAIN: Compared to that terrible itch, the pain of scratching is a dream.
PAIN NEURON: Here that, itch? Brain likes me better than you.
SONALI MALI: But the chemical or whatever is making you itchy isn't actually going away. And after a while, the pain sensation will stop overriding the itch sensation, and you'll continue to experience it.
ITCH NEURON: Like it or not, that's when I come back, baby!
BRAIN: Ugh, here we go again.
SONALI MALI: While scratching feels good temporarily, in the end, it can actually make things much worse.
BRAIN: Scratching irritates your skin, and your nails turn a bug bite into a wound. Don't do that.
SONALI MALI: But also, something else that sometimes makes it feel better is some kind of like hot or cold applied to that area.
BRAIN: That's because there are other neurons that sense temperature besides pain and itch neurons. So if you rub an ice cube on an itchy bug bite, a temperature neuron will tell me about coldness, and I won't have to hear about itch or pain. Please try that instead of scratching.
MOLLY BLOOM: Eventually, your immune system will get rid of all the itchy proteins in a mosquito bite, and your itch will go away.
AYAN: In the meantime, try not to scratch.
ROBOTIC VOICE: Brain, Brains, Brains On.
MOLLY BLOOM: Here's something even better than scratching an itch. It's the--
CHILD: (WHISPERS) Mystery sound.
MOLLY BLOOM: Here it is.
[MYSTERY SOUND]
OK. What are your thoughts.
AYAN: Well, firstly, I think it's like a video game, like Space Invaders maybe.
MOLLY BLOOM: Kind of sounds like laser-y?
AYAN: Yeah, like an arcade maybe.
MOLLY BLOOM: Good thinking. We'll hear it again and give you another chance to guess a little bit later in the show.
AYAN: All righty.
[MUSIC PLAYING]
MOLLY BLOOM: We've got an episode all about teeth coming up.
AYAN: And we want to hear from you.
MOLLY BLOOM: If you were the tooth fairy, what would you leave for kids who have lost teeth and why? So
AYAN: Ayan, what would you leave as a present for lost teeth? I'll probably give them cookies or something because sometimes-- you know, they're really good, so I would probably choose cookies.
MOLLY BLOOM: Would you put the cookie under the pillow? Or would that get too messy?
AYAN: I feel like it would be too messy. I would only put it under the pillow if they're in like a Ziploc. But even then, they might get like-- I don't know, kind of like cracked or something. So if they have a nightstand or something, I would put them there with a little letter that says, from the tooth fairy.
MOLLY BLOOM: I love that idea. Well, listeners, send us your answers too at brainson.org/contact. And while you're there, you can send us your mystery sounds, drawings, and questions.
AYAN: Like this one.
GRAHAM: Hi. My name is Graham. My question is, what is a solar flare?
MOLLY BLOOM: We'll answer that question during our Moment of Um, and we'll read the latest group of listeners to be added to the Brains Honor Roll, all at the end of the show.
AYAN: So keep listening.
MOLLY BLOOM: You're listening to Brains On from American Public Media. I'm Molly.
AYAN: I'm Ayan.
MARC SANCHEZ: I'm Marc.
SANDEN TOTTEN: And I'm Sanden.
MARC SANCHEZ: And we are--
MARC AND SANDEN: The Hoax Hunters.
SANDEN TOTTEN: Yeah.
MARC SANCHEZ: Can I get some music?
[MUSIC PLAYING]
MARC AND SANDEN: (SINGING) We like myths, but we hate getting tricked. Yeah! We like myths, but we hate getting tricked. Yeah! All right! We like myths, but we hate getting tricked. We hate getting tricked. No, we don't like it.
[MUSIC PLAYING]
SANDEN TOTTEN: Because we love myths, and we hate getting tricked.
MARC SANCHEZ: A hoax is when somebody tricks you into believing something that isn't true.
SANDEN TOTTEN: Today's hoax is all about a fart.
[FART]
MARC SANCHEZ: And it all started in December 2019 when various papers reported about a man from Uganda whose farts were so powerful, they killed mosquitoes.
SANDEN TOTTEN: The British paper, The Sun, published an article all about the man Joe Rwamirama, reporting that bug spray companies hired him to study his glorious gas. According to the article, his farts were so strong, they covered a six-mile radius.
MARC SANCHEZ: Now that is one tremendous toot. Maybe too tremendous.
SANDEN TOTTEN: You're right to be suspicious. Turns out, his farts weren't the only thing that smelled funny. The article was completely made up.
[ELECTRIC GUITAR]
MAN: Get hoaxed.
SANDEN TOTTEN: The original article came from a satirical news website. That is to say, it was all a joke.
MARC SANCHEZ: But other outlets didn't catch that part, so they thought it was real. And they retold the story without any fact checking.
SANDEN TOTTEN: Big mistake.
MARC SANCHEZ: Huge! And before you knew it, the story had spread like a fart next to a fan
MAN: Everyone got hoaxed.
[EXCLAIMS]
SANDEN TOTTEN: This isn't the first bogus story about bug repellents. Turns out, there's a lot of bad information out there.
MARC SANCHEZ: Yeah, like rub a dryer sheet on your arms, eat garlic, or pour mouthwash all over your porch?
SANDEN TOTTEN: But those claims don't have much scientific evidence to back them up. However, there are lots of insect repellents that are backed by research and testing. Yeah.
[MUSIC PLAYING]
MARC SANCHEZ: Chris Potter has done a lot of research himself. He's a professor of neuroscience at Johns Hopkins University.
CHRIS POTTER: If you go to the drugstore, the most commonly used one is called DEET. It stands for N,N-diethyl-3-methyl-amide. But that's quite a mouthful, so it's just been abbreviated as DEET. That's like the gold standard for insect repellents.
SANDEN TOTTEN: Chris says DEET works in a couple of different ways. First, it changes the way you smell to a mosquito.
CHRIS POTTER: So when you put DEET on your skin, it prevents other odors on your skin from being volatiles, meaning they don't come off your skin as they would normally do. And so what that does is it kind of keeps your odors to yourself. So the first thing that DEET can do is it essentially changes the way you smell. You just don't smell like a human anymore.
MARC SANCHEZ: So when a mosquito is trying to find you, it just can't.
CHRIS POTTER: The second thing that can do is that it can activate neurons on the antenna, which is essentially the nose of the mosquito. And when it activates these neurons in the mosquito's nose, it smells bad to the mosquito.
SANDEN TOTTEN: Smell you later, skeeters. [MOCKING]
CHRIS POTTER: And the third thing that DEET can do is that when an insect like a mosquito lands on your skin-- there are neurons in its feet. And so when they land on us, they can actually use this for tasting. So they're essentially tasting us when they land on us. And if you have DEET on your skin, this tastes really bad to a mosquito. So as soon as it lands on your skin, and it touches DEET, it tastes bad, and it'll jump away.
MARC AND SANDEN: Tuh-DEET!
MARC SANCHEZ: But I'm going to be honest, these mosquitoes aren't really bothering me.
SANDEN TOTTEN: What? Ugh, I'm itching like crazy over here. Ooh. Why is it that Marc is fine and dandy, but I'm out here getting eaten alive? Ugh.
CHRIS POTTER: Everybody smells good to a mosquito, but some people smell better than others. And so the odor we give off, it's a very complex odor, like a bouquet, I guess. There's bacteria and other things that are on your skin that take your odors, take your chemicals and turn it into odors. And so it's a combination of all those things that make you smell the way you do. Some people are giving off certain chemicals that allow them to smell better to mosquitoes. Other people actually have some chemicals on their skin that don't smell quite as nice to a mosquito.
MARC SANCHEZ: I guess I lucked out with these genius genes. Shout out to Mom and Dad! Woot woot!
CHRIS POTTER: One thing to realize is that sometimes what happens is that people just don't react to the mosquito bites. And so they might just be just as attractive to mosquitoes and being bitten by mosquitoes, but they just don't realize it because they just don't react to the bites.
SANDEN TOTTEN: Well, even if I get all bit up, at least mosquitoes appreciate my smell. There's notes of buttered popcorn, time machine dust, and just a hint of vanilla.
[SNIFFING]
MARC SANCHEZ: Mm, that's not bad.
SANDEN TOTTEN: Thanks, Chris, for helping out.
CHRIS POTTER: Yeah, no problem. Thanks for calling.
[MUSIC PLAYING]
MARC SANCHEZ: That's all for Hoax Hunters today. Remember to check your sources, folks.
SANDEN TOTTEN: And always look for evidence that backs up a big claim or a lofty headline.
MARC SANCHEZ: Because you definitely don't want to get hoaxed.
MARC AND SANDEN: Hoax Hunters, out!
MOLLY BLOOM: OK. Ayan, we still need your ears to point to the true identity of this mystery sound. Let's hear it again.
[MYSTERY SOUND]
The last time, you were thinking something video game related. Do you have any new thoughts?
AYAN: Maybe like laser tag.
MOLLY BLOOM: Ooh, you play laser tag?
AYAN: Well, with my friends. For birthday parties. we play laser tag lots of times. I've played it a lot, so.
MOLLY BLOOM: Can you describe what laser tag is for someone who might not know?
AYAN: OK. So for laser tag, you pretty much have these vests, kind of with like sensors on them. And pretty much, you have kind of like a laser gun, I would say. And it used, like, a red light. And if you hit the sensor, they're out. And they have to go to a recharging station so they can get back in. And when you get hit, it makes an odd noise, kind of like the one it just showed in the mystery sound.
MOLLY BLOOM: You ready to hear the answer?
AYAN: Yes.
MOLLY BLOOM: Here it is.
BRAZEN: My name is Brazen from Seattle, Washington. That was the sound of me dropping a rock into a six-inch diameter steel pipe that is an abandoned well on our rural property in Bremerton, Washington. We think the old well is 250 feet deep. My dad is so excited that there is water at the bottom.
AYAN: That is oddly specific, but OK.
MOLLY BLOOM: Yes, that is very specific. But yeah, that sort of laser-like noise is the sound of the rock echoing--
AYAN: Like going down the pipe.
MOLLY BLOOM: Exactly. And it's really deep at the ground, so it just kind of keeps going and going and going. And then it lands in the water at the bottom.
[FADING LASER SOUNDS]
AYAN: Mosquitoes are tiny creatures, but they have a big impact on humans.
MOLLY BLOOM: Here's Lyric Bartholomay again.
LYRIC BARTHOLOMAY: The mosquito that transmits malaria parasites in Africa is the most dangerous animal on the planet, by any measure, because of the number of people that die after having been bitten by those mosquitoes.
AYAN: So that brings us to this question from Brian.
BRIAN: My question is, do mosquitoes have a purpose to be on the Earth? They go around annoying everybody. They suck your blood. So what are they meant for?
MOLLY BLOOM: Lyric says that even though mosquitoes are a nuisance and potentially dangerous, they play an important role in the ecosystem.
LYRIC BARTHOLOMAY: The environment benefits from mosquitoes being there because mosquitoes feed all kinds of animals. You can find the mosquitoes, lots of mosquitoes in the bellies of ducks and frogs and all kinds of different animals. And so they're a really essential part of the food chain in places where we do a really good job of controlling mosquitoes and just take all of them out of the environment.
It can have an impact on things like bird reproduction. So a bird lays an egg, and she needs proper nourishment in order to lay healthy eggs too. And so if she doesn't have all the mosquitoes to feed on, she might have sort of brittle eggshells. Now I've told you that, but there's more than 3,000 kinds of mosquito. For example, in the state of Iowa with 55 different kinds of mosquitoes that we see, maybe about five of them are important in terms of disease transmission.
MOLLY BLOOM: Lyric says that instead of getting rid of all mosquitoes, scientists are working on ways to control the small number of mosquito species that do spread disease and pathogens.
LYRIC BARTHOLOMAY: Yeah. There are all kinds of really beautiful and creative ways that people are coming up with.
MOLLY BLOOM: One strategy involves infecting mosquitoes with a bacteria called Wolbachia. This bacteria is a natural one already living in some mosquitoes, just like all the bacteria we have living in our guts.
LYRIC BARTHOLOMAY: What we've learned is that mosquitoes that are infected with Wolbachia are also not readily infected with other things. So it's a really powerful potential tool.
MOLLY BLOOM: So mosquitoes with this Wolbachia shouldn't be able to pick up and spread other diseases, making them a pest but not deadly.
LYRIC BARTHOLOMAY: Sure they're dangerous animals, but I think we should appreciate how important they are. How can we appreciate the mosquitoes and understand their diversity and how they fit in an ecosystem but also try and control the really dangerous ones for the benefit of people's health.
[THEME MUSIC]
MOLLY BLOOM: Female mosquitoes use six different mouthparts to bite you.
AYAN: It's the mosquito spit that makes your bug bite itch.
MOLLY BLOOM: Scratching a bug bite feels good because it gives your brain a break from an itch.
AYAN: But try not to scratch. The itch will stop when your immune system cleans up all of the mosquito spit.
MOLLY BLOOM: All humans smell good to mosquitoes, unless we wear repellents like DEET. Then they can't smell us at all.
AYAN: Some mosquitoes spread dangerous diseases, but others make great snacks for birds and spiders.
MOLLY BLOOM: That's it for this episode of Brains On.
AYAN: Brains On is produced by Menaka Wilhelm, Sanden Totten, Marc Sanchez, and Molly Bloom.
MOLLY BLOOM: We had production help from [INAUDIBLE] Georgie, Ruby Guthrie, and Christina Lopez and engineering help from Veronica Rodriguez, Eric Romani, and Sean [INAUDIBLE]. Special thanks to Jennifer and Josh Ellman, Christina Lopez, Rosie duPont, and John Sklaroff.
AYAN: Brains On is a non-profit public radio program.
MOLLY BLOOM: You can support the show at brainson.org/fans. There you can find links to donate, or join our free fan club, or check out our Brains On merch.
AYAN: We now have brains on shirts, baseball hats, and face masks.
MOLLY BLOOM: And you can buy the Brains On book there too. That's brainson.org/fans.
AYAN: And now, before we go, it's time for the Moment of Um.
[CHORUS OF UMS]
GRAHAM: What is a solar flare?
MOLLY BLOOM: Here with the answer is Dr. Nicola Fox. She's the director of NASA's heliophysics division. Heliophysics is the science of understanding the sun.
NICOLA FOX: Oh, solar flares are wonderful. So they're some of the most beautiful things that you see happening on our sun's the surface. So if you look at the sun, invisible light-- obviously, you don't look at the sun directly, but if you use a filter, or you look at images on the web, and you look at a sun in visible light, you'll see it's kind of a uniform sphere. But it may have a few little dark splotches on the sun, and they are sun spots. And they are actually associated with very intense active regions on the sun.
From time to time, these active regions get sort of so much energy kind of pent up inside that active region that they have to explode and sort of release the energy out away from the active region. So that it's just like this big explosion of light and heat and also radiation that comes out with it. And they can actually interfere with us here at Earth.
They can interact with our Earth's magnetic field, and they can cause very big space weather events here at Earth-- things like beautiful Aurora that you can see in the sky, also issues with power grids, problems with spacecraft, with GPS navigation. And so that's one of the reasons that we really, really want to understand our star so well so that we can predict space weather, and we can better protect life and society here on Earth.
[MUSIC PLAYING]
[CHORUS OF UMS]
MOLLY BLOOM: Here's a list of names that shines as bright as the sun. It's the Brains Honor Roll. These are the incredible listeners who share their questions, ideas, mystery sounds, drawings, and high fives with us.
[LISTING HONOR ROLL]
[MUSIC PLAYING]
MOLLY BLOOM: We'll be back soon with more answers to your questions.
AYAN: Thanks for listening!
Transcription services provided by 3Play Media.
