ananyo writes "Researchers have tagged every single worker in entire colonies and used a computer to track them, accumulating what they say is the largest-ever data set on ant interactions. The biologists have found that the workers fall into three social groups that perform different roles: nursing the queen and young; cleaning the colony; and foraging for food. The insects, they found, tend to graduate from one group to another as they age. By creating heat maps to represent the workers’ positions, Mersch's team showed that nurses and foragers stick to their own company and seldom mix, even if the colony’s entrance and brood chamber are close together (abstract). Cleaners are more widely dispersed, patrolling the whole colony and interacting with both of the other groups. 'The ants can probably be in any place within their enclosures in less than a minute,' says Mersch, 'but even in these simple spaces, they organize into these spatial groups.'"