Do Humans and Bats Have Much in Common?

Sometimes the truth about the animal kingdom can drive you, well, batty. Case in point: You probably don't think of bats as having hands, but in reality, most of a bat's wing is the fingers of its hand, similar in some ways to a human arm and hand.

The main structural difference is that a bat's fingers are very long -- about the same length as its forearm -- and they basically form the outer structure of its wing. A double membrane of skin lies over the fingers, connecting them to the rest of the arm, and creates the flying surface we know as a wing. The bat's thumb protrudes up and out of the middle of the wing and is used for movement when the bat is not in flight, such as for climbing. The bat's unique hand formation helps us understand why they are so flexible in the air.

Yet even among bats, there are different wing shapes and sizes. High-aspect ratio wings are narrow and sleek and ideal for soaring at high speeds, while low-aspect ratio wings are rounded and short, so while they don't allow the bat to fly as quickly, they are perfect for maneuvering. All of this bat anatomy might come as a surprise, but it shouldn't: Bats belong to the scientific order Chiroptera, which means "hand wing."

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