In the final programme, Charlotte Uhlenbroek explores how animals communicate in a crowd where everyone looks and sounds the same. How do birds and fish signal to move in unison in a huge flock or shoal? Charlotte demonstrates, with the help of computer generated animals, that it is all down to three simple rules. Some animals behave like Dr Jekyll and Mr Hyde - but what signals them to change? The first is a shy retiring bright green locust and the second is a yellow and black social locust that can form biblical-like plagues. They both look and behave totally differently, but are the same age, sex and species, and even have the same mother. Charlotte reveals the secret signal that makes this dramatic transformation by tickling the locust's G-spot on its hind legs. Charlotte also has the extraordinary privilege of listening to ants talking. She has the rather less fortunate experience of vicious fire ants attacking her legs. They all sting at the same time by shouting to each other, all at once, using sound that we cannot hear. Monkeys and apes spend about twenty percent of their time grooming each other to maintain friendships, humans on the other hand spend about twenty percent of their time gossiping! For humans, bonding with words is quick and efficient, and language helps us to share experiences. Our urge to bond is so strong that it even crosses barriers to other animals. We constantly talk with our pets. Yet Charlotte concludes, "The real challenge for us is to continue to learn other animals' language, and understand what they are saying to each other. Only then will we be able to talk with the animals." Show less