The Eastern Gray Squirrel is a tree squirrel that is native to the eastern to midwestern United States and the eastern provinces of Canada. They were first recorded by zoologists in the Carolinas and are still extremely common there. They were introduced into a variety of locations on the west coast of North America and at the turn of the 20th century, the species was introduced into South Africa, Italy and England. In the UK, known simply as the Grey squirrel, the species has almost completely wiped out the native Red squirrel. They have no natural predators and this has added to their rapid population growth and led to the species being classed as a pest. The Eastern Grey Squirrel is common throughout most of its natural range and wherever it has been introduced. It readily becomes tolerant of humans and learns to take food left or offered by picnickers.
As its name suggests, the Eastern Grey Squirrel's fur is predominantly grey, but it can have a reddish tinge. It has a white belly and a large bushy tail. In parts of Canada and along the West Coast, whole colonies of melanistic and albino (white) squirrels exist.
This squirrel is a scatter-hoarder, which means that it hoards food in numerous small caches, for recovery later. Some of these caches (especially those made near the site of a sudden abundance of food) are retrieved within hours or days, for re-burial in a more secure site. Others are not retrieved until months later. It has been estimated that each squirrel makes several thousand caches each season. The squirrels have very accurate spatial memory for the locations of these caches, and use distant and nearby landmarks to retrieve them. Olfaction is used only once the squirrel is within close range (a few centimetres at most) of the cache site.
They build a type of nest mainly out of dry leaves and twigs, known as a drey, in the forks of trees. Sometimes they will also attempt to build a nest in the attic or exterior walls of houses, often to the great annoyance and frustration of the homeowner. They have also been known to dig up bulbs from gardens. Their reputation for these habits has led some to call them "tree rats" or "rats with fuzzy tails".
Predators include hawks, mustelids, skunks, raccoons, snakes and owls. On occasion, this squirrel may lose part of its tail while escaping a predator.