A nocturnal mammal, widespread in tropical and temperate regions; hibernates in winter in cold areas; usually hangs head-down at rest; the only mammal capable of sustained flight (the wing is a web of skin stretched between elongated fingers and joined to the rear legs and tail); probably evolved to exploit night-flying insects. Most members of the suborder Microchiroptera eat insects; some also eat fish, frogs, birds, or other bats. They use echolocation to detect prey and avoid obstacles, and have a nose and ears which are often complex in shape.

In contrast, fruit bats (or flying foxes) of the Old World tropics (suborder: Megachiroptera, 170 species) eat fruit and flowers detected by smell. They include the largest bats, with large eyes and a dog-like head (small ears and a long muzzle). They have better vision than other bats, and few use echolocation. A quarter of living mammal species are bats. The name fruit bat is also used for genus Artibeus (14 fruit-eating species) from the New World tropics (suborder: Microchiroptera; family: Phyllostomidae). (Order: Chiroptera, 951 species).