Now Minttumaaria Hannonen and Liselotte Sundstrom of the University of Helsinki have discovered a different side of the ant’s personality, and it isn’t pretty. According to their paper in last week’s Nature journal, ants engage in blatant nepotism. The scientists first recorded the genotypes of a group of Formica fusca, a common species, then observed how they behaved toward their kin. Worker ants demonstrated a remarkable ability to distinguish sisters from half-sisters and unrelated neighbors. (Ants in a colony are almost always female.) They were even able to sniff out alien bloodlines among larvae. What’s more, the ants tended to favor their close relations, jockeying for their brood’s position in the colony and getting more sustenance to little larval sisters. Sometimes they even committed infanticide–eating neighbors’ pupae. Why have scientists had a tough time seeing this behavior? Sundstrom thinks it’s because colonies allow some nepotism, but not too much–sort of like the mob. A little aggression is OK, but rock the boat and you’re liable to get your kneecaps broken.
