Eastern chipmunk, a striped ground squirrel found mostly in eastern North America. Eastern chipmunks have five dark and two light stripes on their backs, extending from head to rump, and two stripes on their long, bushy tails. They are distinguished from other ground squirrels by the white stripes above and below their eyes.
Chipmunks often make their homes in sparse forests or farms, where they can build the entrances to their lodges in stone walls, broken trees, or thick underbrush. A lodge consists of a maze of tunnels leading to a large, leaf-lined nest. Chipmunks spend most of the daylight hours outdoors but head for their lodges before nightfall. Although they are excellent climbers, chipmunks live primarily on the ground.
Chipmunks eat nuts, seeds, insects, and occasionally birds’ eggs. Like all ground squirrels, they have large cheek pouches, sometimes extending as far back as their shoulders, in which they can store food. They collect and store nuts and seeds through the summer and fall. When the weather starts to get cool, all the chipmunks in a region suddenly disappear into their lodges, where they begin hibernation. On warm winter days one can often see chipmunk pawprints in the snow, as they will sometimes wake up and leave their lodges for brief periods when the temperature rises.
Mating season for Eastern chipmunks is mid-March to early April. The gestation period is 31 days, after which a litter of three to six is born. Baby chipmunks leave the lodge after one month and are mature by July.
The chipmunk most likely got its name from the noise it makes, which sounds like a loud “cheep.” You can occasionally see a chipmunk hanging upside down from a tree branch “cheeping” its call.
Source: C++ in a Nutshell, O’Reilly & Associates, Inc