Bat

A bat is a mammal in the order Chiroptera. Their most distinguishing feature is that their forelimbs are developed as wings, making them the only mammals in the world naturally capable of flight (though other mammals, such as flying squirrels and gliding flying possums, can glide for limited distances). The word Chiroptera comes from the Greek words cheir "hand" and pteron "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.