We have a lot to learn from ants. This episode digs into the hierarchy of ant colonies (spoiler alert: there is none) and why they walk in a straight line (spoiler alert: they don’t).
Scientists are also studying how ants spread out and search. This work is teaching us about how cancer spreads, how the internet can be improved, and could even give us new ways to explore Mars.
Our guests for this episode are biologist Deborah Gordon, who has been studying ants for the last 30 years and runs an ant lab at Stanford University, and computer scientist Melanie Moses, who has translated the search functions of ants into an algorithm for robots.
Want to learn more about ants? Sign up for the Brains On newsletter. In it you’ll find questions designed to help go beyond the show, book recommendations, and a cool citizen science project (the same experiment NASA tested with ants in space).
Walk like an ant, search like an ant
There’s a lost diamond ring in a football field. You and 100 of your closest friends are on the search team. Oh also, you’re blindfolded. You would likely start out clumsily, unwittingly going over the same stretch of grass multiple times.
If 100 ants were given a similar task — say, to find a piece of food — the search would look quite different and would be much more efficient.
Ants use something called “collective search.” Deborah Gordon, an entomologist from Stanford University, says the ant search would go something like this: If ants are searching an area, they’ll start walking. If they don’t bump into any other ants, they keep right on walking until they do. “They just use the rate at which they meet, and it’s a measure of how many other ants are searching that same area,” Gordon says. Ants can quickly cover a lot of ground this way.
When it comes to our lost diamond ring, Gordon, who has been studying ants for 30 years, says we can employ the same collective search methods as ants and find the ring much more quickly than if we were left to our own devices.
And there are many other ways humans can benefit from understanding collective search, and not just in some-made-up-diamond-ring-on-some-made-up-football-field kind of way. Cancer researchers are turning to collective search to see if it can help them predict how the disease spreads. Collective search is also similar to the way data files are delivered across the internet (Transfer Control Protocol). Robots are getting in on the action too. Algorithms based on the same collective search patterns are being used to help in space exploration and rescue missions.
And remember that blindfold in our hypothetical scenario? Well, ants are basically blindfolded all the time. There are over 14,000 species of ants, and the majority can’t see well. They have a powerful sense of smell that they use a navigation tool. Instead they use their antennae sense of smell as a powerful navigation tool.
If an ant is out foraging for food and happens to bump into something nutritious, it will leave a chemical, pheromone path for other ants to pick up with their antennae. Each ant follows the path and leaves its own trail until the food is gone.
They also use their sense of smell to communicate with each other. Gordon explains, “[Ants] are smelling this layer of grease that they have on their bodies. And that grease has a smell that tells the other ant what job it’s been doing and whether it belongs to the same colony.”