There are around 52 species in this family of small to medium-sized bats. They are found in tropical and subtropical areas in North America, South America, Central America, Asia, Africa, and Australia and surrounding islands.
Sac-winged bats get their name from a scent gland sac on the front edge of the wings of many species. The scent gland is used by the bats to mark their territory. Sheath-tailed bats get their name from a membrane that encloses all but a small bit of their short tails.
The bats in this family have large ears and small eyes and are usually gray or brown. They roost on vertical surfaces like tree trunks, the sides of buildings, cave walls, or cliffsides.