An order of "Mammalia", distinguished by greatly elongated fingerbones supporting a membrane or "wing" attached to the posterior limbs and the side of the body, and adapted for flight; the bats: Most Cheiroptera or Chiroptera are insectivorous, however, some of them are fruit-eaters, nectar consumers, consumers of small vertebrates, and a few are even bloodsuckers.

Chiroptera usually sleep hanging upside down in caves during the day and fly out at night and, although they have small eyes, bats are able to emit and to hear extremely high-pitched sounds, the echoes of which enable them to avoid hitting objects and each other when flying.