0 a type of squirrel (= a small mammal with a long tail that climbs trees) that has skin joining its front and back legs so it can travel short distances through the air: --
He studies small mammals - mice, chipmunks, and flying squirrels - from the research station on Douglas Lake.
All birds and flying mammals, such as bats and flying squirrels, have wings attached to their forelimbs.
Autumn nights are best for observing flying squirrels because they are busy gathering food for winter.