A bat is a mammal in the order Chiroptera. The forelimbs of all bats are developed as wings making them the only mammals naturally capable of flight(though other mammals, such as flying squirrels, flying possums and colugos, can glide for limited distances). The word Chiroptera comes from the Greek words cheir (χειρ) "hand" and pteron (πτερον) "wing," as the structure of the open wing is very similar to an outspread human hand with a membrane(patagium) between the fingers that also stretches between hand and body.
A measure of the success of bats is their estimated total of about 1,100 species worldwide, accounting for about 20 percent of all mammal species. About 70 percent of bats are insectivores. Most of the rest are frugivores , with a few species being carnivorous. Bats are present throughout most of the world. Bats perform a vital ecological role by pollinating, and flowers also serve an important role in seed dispersal. Many tropical plants are entirely dependent on bats.
Bats range in size from Kitti’s Hog-nosed Bat measuring 29–33 mm (1.14–1.30 in) in length and 2 g (0.07 oz) in mass, to the Giant golden-crowned flying fox which has a wing span of 1.5 m (5 ft) and weighs approximately 1.2 kg (3 lb).
