Bats are mammals 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.
About 70% of bats are insectivores. Most of the rest are frugivores, or fruit eaters.
A few species, such as the fish-eating bat, feed from animals other than insects, with the vampire bats being hematophagous. Bats are one of the few animals in the World that practice oral sex!
They do this in order to make the intercourse last longer.