The chipmunks are small, striped ground squirrels. Of the 24 species of chipmunk, all but one, the Siberian chipmunk, are native to North America. While most species of chipmunks are found in western North America, the eastern chipmunk inhabits deciduous forests and parkland throughout most of the eastern United States and southern Canada, ranging as far west as North Dakota and eastern Oklahoma and Texas.
The eastern chipmunk has a body about 5-7 inches in length, and a 3-4 inch tail. It is reddish-brown on the back and sides, with a white belly. The most noticeable feature is the black and white stripes--a white stripe bordered by black stripes on each side, and a black stripe down the middle of the back, and a white stripe above and below each eye.
Although the eastern chipmunk climbs trees with ease, it is classified as a ground squirrel. It nests underground, building extensive tunnel systems, often with multiple entrances. It prefers wooded areas with rocks and bushes to provide shelter from predators. Except when mating and raising young, eastern chipmunks are solitary and territorial, defending their burrows from intruders. Females usually have one litter per year, with 3-5 young, although in more southern areas they may have two litters per year. The young stay underground until they are about six weeks old.
Eastern chipmunks are active primarily during the day. They eat a mostly herbivorous diet that includes nuts, seeds, bulbs, acorns, mushrooms, fruit and berries, and corn if available. They may also eat snails, insects, birds' eggs, and even small mammals such as young mice. Chipmunks have cheek pouches that they use to transport food to their burrows for storage. Eastern chipmunks do not hibernate, but they may spend a lot of time sleeping during the winter, seldom venturing out of the nest and living on food stored underground.
There are different theories about where the word "chipmunk" came from. One theory is that it refers to the "chip" sound that these tiny squirrels make. Another is that it is derived from an Ottawa word "ajidamoonh", which literally translates "one who descends trees headfirst."