A squirrel is a rodent of the Sciuridae family. Three types of squirrels are ground squirrels, tree squirrels, and flying squirrels. In North America, the two most common species of squirrel are the Eastern Gray Squirrel and the Red Squirrel, both tree squirrels. The prairie dog and chipmunk are both types of ground squirrel. Squirrels are "scatter-hoarders", which means they gather and hoard food in caches in multiple locations.