To look inside an ant nest is to think about an alien civilization. The busy mass of worker ants beneath an upturned stone is both strangely similar to human society and strikingly different. Like us, ants build structures, find food, defend their societies and manage waste. They must be well-organized to do all these. For example, leaf-cutting ants have special waste disposal areas for storing hazardous waste and a team of ‘waste-disposal ants’ dedicated to keeping the nest clean. But ants achieve this familiar end result in a very different way to humans. Human societies have centralized control. In other words, someone tells us what to do. Ants, in contrast, have decentralized control, and neither the queen nor any other ant directs work. They are the ultimate self-starters, following specific, but flexible, rules in certain situations.