We all know people who find it hilarious to prod and poke, pinch and tickle, all in the name of fun. But are humans the only ones who like to tease each other? Or are other animals in on the act? Ian Sample talks to Prof Erica Cartmill about her work on apes and teasing and asks, given how annoying teasing is, why do apes, and humans, do it?. Help support our independent journalism at <a href="https://www.theguardian.com/sciencepod">theguardian.com/sciencepod</a>
