Squirrels are rodents and the four species do not interbreed. Born blind and hairless, young are dependent upon their mother for up to two months. In early spring, squirrels eat buds, a high-energy food. They eat the buds and flowers of red and sugar maples in April, and later may feed on the winged fruits of red maple. These foods have a high moisture content that supplies squirrels' water needs, although grays will drink from available ground water sources.
Grays smell out nuts which they bury for winter food.
Unrecovered nuts may sprout and grow into trees. In this way, squirrels help ensure continual forest growth. Grays are probably the wariest of Pennsylvania's squirrels. Hawks, owls, foxes and tree-climbing snakes occasionally kill young squirrels, but adults are not easily taken. A maximum life span for a wild gray squirrel could be 10 years or even longer, but few live more than two or three years.