When we think about animal behaviour, we often assume that the animals are in charge of their own actions. That’s often not the case. At the TED2014 conference in Vancouver last week, I gave a talk on the fascinating and macabre world of mind-controlling parasites, from the tapeworm that makes shrimps sociable to the wasp that takes cockroaches for walks, with special shout-outs to the NSA and Elizabeth Gilbert. Take a look.