Bats mimic hornets when owls are nearby

IN THE ANIMAL kingdom, mimics are a dime a dozen. Stick insects pretend to be twigs. Hawk-moth caterpillars resemble venomous snakes. Edible heliconid butterflies disguise themselves with the wing patterns of noxious ones, and noxious ones copy each other to make it easier for predators to learn what not to eat.All these examples, though, are visual. Auditory mimicry is rarer. But, as he describes in , Danilo Russo of the University of Naples Federico II thinks he has found a novel case of it. Some bats, he believes, mimic angry bees, wasps and hornets in order to scare away owls that might otherwise eat them.