Naked Selfless Mole Rats

Naked mole rats, habitants of northeast Africa, live in insectlike colonies dominated by a single breeding queen, a life-style unique among mammals. Recently, Paul Sherman, an animal behaviorist at Cornell, and Timothy Judd, a graduate student at Colorado State University, have observed another hive-like trait among the pink, gerbil-size animals: some of them behave--at least in laboratory colonies--like selfless worker bees, providing food for the rest of a sometimes indolent colony. When a mole rat scout finds an easy-to-carry bit of root or tuber, instead of chowing down on the spot, it scurries home with the food, chirping all the way. As it approaches the nest, other mole rats are alerted by the chirps, and they follow the scout’s trail of scent back to the food’s source. The scout, meanwhile, continues on to the nest, where it waves the food around, still chirping, as if to inform others that there’s food to be found. Larger mole rats, who lounge around, ostensibly defending the nest, take the food from the scout. Eventually the scout heads out with other foragers to bring back food; they don’t get to eat until the rest of the colony is sated. These animals are extremely altruistic, much like the workers in colonies of social insects, says Sherman. They are working for the good of the colony.