The term "patagium" refers to a membrane or wing-like structure found in certain animals, particularly in birds and bats. This structure aids in flight by providing a surface area that can generate lift. In birds, the patagium is located between the body and the wing, while in bats, it stretches from the body to the fingers, allowing for greater maneuverability in the air. In addition to birds and bats, the patagium is also present in some gliding mammals, such as flying squirrels. These animals use their patagium to glide between trees, enhancing their ability to travel and escape predators. The patagium plays a crucial role in the locomotion of these species.