Bats are
mammals of the
order Chiroptera (; from the
Greek χείρ -
cheir, "hand" and πτερόν -
pteron, "wing") whose forelimbs form webbed
wings, making them the only
mammals naturally capable of true and sustained
flight. By contrast, other mammals said to fly, such as
flying squirrels,
gliding possums, and
colugos, can only
glide for short distances. Bats do not flap their entire forelimbs, as
birds do, but instead flap their spread-out
digits, which are very long and covered with a thin
membrane or
patagium.
