BAT,  a name for any member of the zoological order Chiroptera (q.v.). Bats are insectivorous animals modified for flight, with slight powers of progression on the ground; the patagium or "flying-membrane" of some squirrels and of Galeopithecus (q.v.) probably indicates the way in which the modification was effected. They are distributed throughout the world, but are most abundant in the tropics and the warmer parts of the temperate zones; within these limits the largest forms occur. There is great variation in size; the Malay "flying-fox" (Pteropus edulis) measures about a foot in the head and body, and has a wing-spread of 5 ft.; while in the smaller forms the head and body may be only about 2 in., and the wing-spread no more than a foot. The coloration is generally sombre, but to this there are exceptions; the fruit-bats are brownish yellow or russet on the under surface; two South American species are white; Blainville's chin-leafed bat is bright orange; and the Indian painted bat (Cerivoula picta) with its deep orange dress, spotted with black on the wing-membranes, has reminded observers of a large butterfly. In habits bats are social, nocturnal and crepuscular; the insect-eating species feed on the wing, in winter in the temperate regions they migrate to a warmer climate, or hibernate, as do the British bats. The sense-organs are highly developed; the wing-membranes are exceedingly sensitive; the nose-leaf is also an organ of perception, and the external ear is specially modified to receive sound-waves. Most bats are insect-eaters, but the tropical "flying foxes" or fox-bats of the Old World live on fruit; some are blood-suckers, and two feed on small fish. Twelve species are British, among which are the pipistrelle (Pipistrellus pygmaeus, or P. pipistrellus), the long-eared bat (Plecotus auritus), the noctule (Pipistrellus [Pterygistes] noctulus) the greater and lesser horseshoe bats (Rhinolophus ferrum-equinum and R. hipposiderus), etc. (See Flying-fox and Vampire.)
 M. E. bakke, the change to "bat" having apparently been influenced by Lat. batta, blatta, moth. The word is thus distinct from the other common term "bat," the implement for striking, which is probably connected with Fr. battre, though a Celtic or simply onomatopoetic origin has been suggested.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)