Flying Squirrel

The Petauristinae (also called Pteromyinae) is a subfamily of squirrel (family Sciuridae). They are usually called flying squirrels. There are 36 species in this subfamily, the largest of which is the Woolly Flying Squirrel (Eupetaurus cinereus). The 2 species of the genus Glaucomys (Glaucomys sabrinus and Glaucomys volans) are native to North America, and it is these that are commonly meant when the name "flying squirrel" is used in English, although the term is frequently also used by Europeans to refer to the Siberian flying squirrel (Pteromys volans).

Flying squirrels do not fly in the same sense as birds or bats - they do not employ powered flight. Rather, they glide: once they have launched themselves into the air, they have no means of forward propulsion. They are true gliders: that is, unlike a human-made sailplane, they do not use upcurrents in the air to soar, so they will lose height during a glide. However, they can steer themselves very adroitly while in a glide. They do not steer with their tails, as is commonly but erroneously reported. Steering is accomplished by adjusting tautness of the patagium and positioning of the forelegs. The tail acts as a stabilizer in flight, much like the tail of a kite, and as an adjunct aerofoil when "braking" prior to landing on a tree trunk.

Though their lifespan is only about five years in the wild, flying squirrels often live between 10 and 15 years in captivity. This difference in lifespan is due to these creatures being important prey animals. Predation mortality rates in sub-adults are very high. Predators include arboreal snakes, raccoons, nocturnal owls, marten, fisher, coyote and the domestic house cat.

More information:  http://en.wikipedia.org/flying_squirrel