Why are flying squirrels so named? Interestingly, the term flying is somewhat misleading, since flying squirrels are actually gliding mammals incapable of sustained flight. Their tails act as the stabilizing medium during flight and is of great help when the mammals “brake” just before landing on tree trunks. The steering is accomplished by adjusting the patagium, which is a parachute-like extension of the skin, largely controlled by a small wrist bone.