Chipmunks are small mammals in the order Rodentia, the rodents. Specifically, they are classified with the squirrel-like rodents, the Sciuridae. Chipmunks are divided into two genera: Gallos and Tamias.
North America is home to 17 species of chipmunk, 16 in the West and only one, Tamias striatus, the eastern chipmunk, in the East. The eastern chipmunk is about 5-6 in (12.7-15 cm) long, and the tail adds another 4 in (10 cm) or so to the animal's length. They have stripes on their face and along the length of their body. In all species the tail is bushy, although not quite as much as the tree squirrels. Their eyes are large, their vision is excellent, and their sensitive whiskers give them a well-developed sense of touch.
Like other squirrels, chipmunks are opportunists, making a comfortable home where other animals would not dare. They are generally unafraid of human beings, and are frequent visitors to campgrounds. They are burrowers, digging holes among rocks, under logs, and within scrub, to make a burrow as long as 15 ft (4.6 m) and extend downward about 3 ft (0.9 m).
Like squirrels, chipmunks are active during the day. They emerge from their burrows in the morning to forage on mushrooms, fruits, seeds, berries, and acorns. The chipmunk will store food, particularly items with a long "shelf-life," in its cheek pouches for transport back to the burrow. The Siberian chipmunk can carry more than a quarter of an ounce of seed for half a mile. This food is stored in an underground larder, which can contain between 4.5 and 13 lb (2-5.9 kg) of food. They do not hibernate like bears; instead they become more lethargic than normal during the winter months.
In the spring, the female bears a litter of pups, numbering up to eight, which are born naked, toothless, and with closed eyes. The young grow quickly and are weaned at five weeks, but stay with the female for several months.
Chipmunks can live as long as five years, providing they avoid predators such as weasels, owls, hawks, bobcats, pine martens, and coyotes. Many chipmunks die after eating rodenticide set out for rats; these poisons have effectively eliminated chipmunks in some locations.