Policing egg laying in insect colonies

Kinship by itself can't explain the vigilante justice of some ant, bee, and wasp workers, according to a new analysis of colony life.

In a classic social-insect colony, laying eggs is the job of the queen or queens, though in many species, the workers occasionally lay eggs too. In a practice known as policing, other workers, which are all female, often destroy their nestmates' eggs or even attack a fellow worker caught in the act of egg laying.

Because they are unfertilized, eggs laid by workers and that do hatch only yield sons. That has led many researchers to a potential explanation for egg policing: The workers who do the killing are more closely related to the queen's sons, which are their brothers, than they are to their nestmates' sons, which are nephews.