Oftentimes, there will be more than one father to the pups, which is beneficial to the genetic diversity of a population. Females may potentially have two litters per year, but only in favorable conditions. The average litter a female produces in a single breeding period is between three to four pups per litter, although there are some females that have as many as seven young per litter. Males will stay close to the female until she gives birth to the pups, since the males do not assist in taking care of the young. The gestation period is approximately 40 days.
Females give birth in nests that are made in the hollow of a tree.
Newborn flying squirrels are hairless, with their eyes and ears closed, and weigh less than a quarter of an ounce each. The patagium is visible, although it is seen as just transparent folds of the skin. Female flying squirrels are known for their excellent parenting skills, since they seldom leave their young during the first few weeks upon giving birth. Furthermore, if the female feels threatened she will change the location of her nest. It is not atypical to observe a female flying squirrel gliding from treetop to treetop with a mouthful of young.