A bat's wing is like a human hand. Just like us they have a first finger (thumb), which is curved like a hook. They also have four other fingers, an upper arm, and a forearm (see diagram). Their wings are tough and they stretch. Also, the wings are covered in short prickly hairs. On the wings there is a double layer of skin. Inside of that are bones, blood vessels, nerves and fibers. That is how a bat's wing is like a human hand.