Although almost blind, army ants deploy pheromones so effectively they can create traffic lanes running to and from their nest. This week Peter Evans investigates ants' extraordinary ability to regiment themselves and meets scientists who take their inspiration from ant organisation. From traffic flow to systems analysis and robots, ants are influencing how we solve problems. Some now wonder whether ants will eventually give us insights into other "emergent" properties, such as how the neurones in our brain combine to produce intelligence.