Natural selection for juvenile lizards mimicking noxious beetles.

Adult Eremias lugubris in southern Africa are concealingly colored and move with a typical lizard gait, but the jet-black and white juveniles are conspicuous and forage actively with arched backs. In color, gait, and size, juveniles mimic "oogpister" beetles (Carabidae: Anthia) that spray an acidic, pungent fluid when molested. This unique mimicry, which is believed to be the first reported case of a terrestrial vertebrate mimicking an invertebrate, seems to reduce predation on juvenile lizards.