Flying squirrels have small rounded heads, large black eyes, prominent ears, long whiskers, and well-furred tails. Their fur is dense, soft and silky. The tail is horizontally flattened, the long hairs forming nearly parallel sides and a rounded tip. The general color of the upper portions of the body, head and tail of the southern flying squirrel is drab olive gray, darkest and almost black at the edges of the membranes. he southern flying squirrel is smaller than the northern, and is approximately 8.3-10.0 in long which includes a 3.1-4.3 in tail.

They build many nests, abandoning them when they become dirty and flea-ridden. Nests made of shredded bark, leaves, moss, lichens and feathers are usually located in tree cavities, especially abandoned woodpecker holes, but occasionally in buildings and bird houses. Flying squirrels are the most nocturnal and arboreal of the tree squirrels. Although they forage on the ground, flying squirrels spend most of their time in trees, where they climb, walk, or run along branches, hopping over obstacles.