What anatomical feature allows flying squirrels to glide between trees?

• A. A pair of long wings like birds
• B. A skin flap between the wrists and ankles
• C. A membrane on the belly
• D. A tail membrane

Answer: (B)

Gliding is made possible by a patagial membrane, a loose flap of skin that stretches from the forelimbs to the hindlimbs. In flying squirrels this surface runs between the wrists and ankles, creating a wide wing-like sheet that catches air and lets the animal slide from tree to tree. By spreading its limbs and using the tail for stability, the squirrel can control direction and distance during a glide. This is why describing a skin flap between the wrists and ankles best fits how flying squirrels achieve their gliding locomotion. The other ideas—true wings like birds, a belly-only membrane, or a tail membrane—don’t provide the necessary extended surface or anatomical arrangement for their gliding method.