The term 'winged mammal' is a reference to the BAT, which is a three-letter word. Bats are the only mammals capable of true flight, as opposed to gliding or leaping. They have wings made of skin stretched between their fingers and toes, and they use echolocation to navigate in the dark. Bats are found all over the world, and they play an important role in many ecosystems by consuming large amounts of insects.