Tree squirrels are the squirrels that are common in cities. Many ground squirrel hibernate during cold winters, sleeping in a nest until warm weather arrives. Squirrels can live up to 15 years in captivity. The biggest squirrel is the Indian Giant Squirrel. They eat seeds, nuts, leaves, bulbs, roots, mushrooms, insects, worms, eggs, small birds, and other small animals.
Ground squirrels have pouches in their cheeks in which they carry food to their burrow to store.
Squirrels are hunted by the weasel , fox , hawk , eagle , lynx , bear , and coyote .