Having a sibling is a special thing -- but, wow, can they be annoying! In this episode we’ll look at why our brothers and sisters are so good at pushing our buttons. Plus, is there any truth to the idea that oldest kids are the most mature and the youngest ones are the most charming? We’ll look at the science of personality and birth order. We also visit a sibling drive-thru, get quizzed about animal relationships and answer this question in our Moment of Um: why does rain come in small droplets?