It is actually a gliding squirrel, as they are not physically able to fly. They have a flap of skin called a Patagium which extends from their fore feet to their hind feet, which catches the air like a kite. Their tail acts like a rudder guiding them to quite accurate flights of over 100 feet.
As flying squirrels are strictly nocturnal, they have very large predominant eyes. They eat a variety of seeds and nuts, but are very fond of acorns. They also love bird feeders at night. They will store their cache of nuts in attics and hollow trees until times are lean in the winter. As they are fairly fragile little animals, they don't tolerate the cold well, so fall and winter is when they become a nuisance as they come into our homes for
warmth and to prepare their nests for young.
Flying squirrels are colonial animals, which means that they congregate in extended family units in winter. It is common to have 20 to 30 of these in the attic at one time. Therefore, their nocturnal activity means a lot of noise. Rolling acorns is a common complaint that can usually be associated with these squirrels as well as noises running up and down walls.
Flyers don't usually chew an entry hole, rather they use a structural defect of the house to gain access. This could be an opening under a soffit overhang, hole in a louver screen or a point where the ridge vent is not capped. They do tremendous damage to the insulation, and they create terrible urine odors due to a unique behavioral trait: they use latrine toilets. This means the whole colony will repeatedly go to the bathroom in the same points until the mess is so concentrated that it will leak through the sheetrock or bleed through wooden beams. In either case, the odor is aweful, and nearly impossible to get rid of. They also breed in early spring, but their young will mature sooner.
The control methods used on flying squirrels differ from greys and reds in that we use an eviction and squirrel proofing technique rather than trapping. As there are usually so many to deal with, trapping is not the most practical method of elimination. The eviction is done with one-way exclusion valves made out of metal, which are installed over all of the active entry and exit holes. These are left in place for at least a week to ensure that all of the flyers are out, then their holes are thoroughly sealed. The squirrel proofing means that the entire roofline is inspected and all possible future entry holes are sealed as well to ensure that no squirrels have access into the house.
Flying squirrels prefer the rooflines of contemporary houses, due to the many overlapping roof angles creating inherent gaps in the construction. They also like any houses with dormers or a ridge vent that they can exploit.