What are the only mammals that can fly?

Bats are the answer. Bats are the only mammals capable of true powered flight, using wing membranes stretched over elongated finger bones to fly under their own power, unlike gliding mammals such as flying squirrels.

Bats and True Powered Flight

Bats are the only mammals that can fly in the full biological sense. Their flight is powered, meaning they can flap their wings to take off, maneuver, gain altitude, and travel through the air without simply falling or gliding from a high place. Many bats are nocturnal, and many species use echolocation to navigate and find food, though not every bat relies on it in exactly the same way.

How Bat Wings Work

Bat wings are made from thin skin membranes supported by long finger bones. This structure gives bats flexible wings that can change shape during flight. The combination of lightweight bones, strong flight muscles, and adjustable wing membranes allows bats to make quick turns, hover briefly, and move through dark or crowded spaces with precision.

Flying Versus Gliding Mammals

Some mammals, including flying squirrels, sugar gliders, and colugos, can glide through the air, but gliding is not the same as true flight. Gliding mammals use skin flaps to travel from a higher point to a lower point, while bats generate lift and thrust by flapping their wings. That distinction is why bats are the only mammals correctly described as true flying mammals.