Geography
In the United States, the gray squirrel is a native of the Eastern and Midwestern state, and in Canada it is found in the southeast. However, because this species is so adaptable, it is now found in some parts of the West. The gray squirrel is not native to the British Isles. However, its ability to breed prolifically means that it has displaced the native red squirrel, which is now a rare sight. It is typically found in mature, dense woodlands covering more than about 100 acres.
Nests
Gray squirrels prefer conifer or deciduous trees that provide plentiful food. They tend to build nests in hollow trunks, although sometimes they use abandoned bird nests. The squirrel lines its nest with moss, grasses and feathers. Female squirrels don't share the nest with a male while raising their young, but in winter, nests usually have multiple occupants for the sake of keeping warm.
Hoarders
When a squirrel finds an abundant food source, it is likely to build a temporary food store nearby. The squirrel then transports this food to a more permanent and secure site. Squirrels tend to hoard food in several places, so if one store is destroyed, they still have reserves elsewhere. The squirrel uses landmarks, its spatial memory, and smell to find its many stores.
Food
Gray squirrels love nuts, so it is no surprise that the greatest numbers are found in woodlands that have trees that supply those favorite foods. Woods with plentiful oak trees provide acorns, a food source that vitally lasts through winter storage. Walnut, hickory and beech trees are other important sources. Squirrels also eat wild cherries, various plants and some fungi. In winter the squirrel might eat crops such as corn and wheat, and in summer its squirrel diet can include insects.