 A defining characteristic of this bat is its appearance of having a dark facial "mask", created by nearly black ears and muzzle.The dark skin of its ears, wings and interfemoral membrane, (the membrane between the legs and tail) contrast starkly with the lighter colored fur on the rest of the body.Like all bats, the Eastern small-footed bat has a patagium that connects the body to the forelimbs and tail, aiding in flight.