Roaches don't have complex social structures like bees and ants, but they may still be capable of democratic decisions. To test this idea, a team of researchers presented 50 roaches with three shelters, each of which could hold 50 individuals. Since roaches prefer dark to light, they quickly divided into groups and fled into shelters.

 

But rather than behaving chaotically, the roaches split into groups of 25, half filling two shelters and leaving the third empty. When larger shelters were introduced, the roaches formed a single group in just one of them. According to the study's authors, the roaches were striking a balance between cooperation and competition for resources: "Without elaborate communication, global information, and explicit comparison of available opportunities, the animals are able to assess the availability of resources and adapt the way they form groups among selected sites."