He has written the article below, and has agreed to allow its inclusion on this web page. Birds, you thought at first, but as you watched, there was a fluttering, twisting, dropping motion to their flight that wasn't right for birds. And you were either pleased at the chance to observe them in action, or a little frightened as myths of Dracula and vampires, coupled with concerns about rabies, came to mind. Through the ages, bats have been the stuff of myths and legends, misunderstood and feared.
Bats are mammals.
They are covered with fur, give live birth, and nurse their pups with nipples located on the sides, under their wings. But what makes them unique among mammals is the fact that not only are they perfectly designed for hanging upside-down, like the sloth, but they can also fly. They are the only flying mammal. As the name implies, their wing consists of an arm that ends in a wrist with a thumb and four separate fingers which are webbed with skin, and form the ribs of the wing. When bats aren't flying they fold their fingers back along their forearms out of the way.