Facts about chipmunks

• Need About 15 Hours of Sleep Per Day – At least that’s true of chipmunks in captivity.
• They are a Type of Squirrel – Weighing in at 1 to 5 ounces (28 to 142 grams), chipmunks are among the most diminutive members of the squirrel family. That means these pocket-sized rodents are also related to woodchucks and prairie dogs, which share a branch on the squirrel family tree as well.
• Most Chipmunks Live in North America – There are 25 species of chipmunks, ranging mostly from Canada to Mexico across a variety of stomping grounds from forests to deserts to suburban neighborhoods. Only one species, the Siberian chipmunk, makes its home outside North America, scampering over much of northern Asia as well as in Europe, where it was introduced via the pet trade in the 1960s.
• They Prefer Subterranean Living – While some chipmunks make nests in logs or bushes, most prefer to dig vast underground burrows. These hidden homes typically include a camouflaged entrance hole, tunnel systems that can stretch 10 to 30 feet (3 to 9 meters) long, food storage areas, and a nesting chamber that is kept immaculately clean and lined with leaves and other plant matter.
• Chipmunks Have Many Predators – That includes owls, hawks, weasels, foxes, coyotes, raccoons, bobcats, lynxes, cats, dogs, snakes, and sometimes even their own squirrel cousins. Chipmunks avoid becoming meals by being quick and nimble—and sticking close to home.
• Plenty of Food Sources – Chipmunks aren’t picky eaters and spend a lot of time searching for their next meal, including at bird feeders (as many annoyed homeowners can attest). These omnivores love nuts, berries, seeds, mushrooms, insects, frogs, earthworms, lizards, baby birds, and bird eggs. During late summer and fall, they begin carrying extra food back to their burrow in their ample, stretchy cheek pouches (which can hold a stash three times the size of their head). A hardworking chipmunk can gather as many as 165 acorns in a single day. This foraging also benefits the larger ecosystem; chipmunks spread seeds and important mycorrhizal fungi that live around tree roots, ensuring they thrive.
• Some Chipmunks Hibernate, but Not Continuously – Starting in late October, some chipmunks fall into a deep sleep with a slowed heart rate and lower body temperature for extended periods until March or April. At that point, depending on the year, they may have to dig through as much as three feet of snow to get out of their burrows. Unlike bears, though, chipmunks don’t bulk up their fat stores to sleep through the entire cold season. Instead, according to the Connecticut Department of Energy and Environmental Protection, they wake periodically to dip into their stockpile of nuts and seeds and even venture outside.
• Lifecycle – Eastern chipmunks breed twice a year, once in early spring and then again in July. After a 31-day gestation period, a litter of two to eight young is born in a den underground. The young are born naked, blind and completely helpless, but grow and develop quickly. By the eighth day of life, their stripes begin to appear. After one month, their eyes open and they have become completely covered with fur. At six-weeks old, they are weaned and leave the burrow for the first time. The full-grown chipmunks leave their parents den at eight weeks of age. Both the male and female chipmunks reach sexual maturity by the time they are one-year old. Chipmunks can live up to two years in the wild and have been known to live up to eight years in captivity.
• Chipmunks Are Natural Loners – Despite their reputation for being cuddly, real chipmunks don’t bear much resemblance to their fictional counterparts. They will fiercely defend their territory and chase away any invading strangers.
• Vocalizations – They have a sizable vocal repertoire, announcing everything from territorial claims to terror over nearby predators. Vocalizations include chips, chucks, and trilling alarm calls. Chipmunks are so talkative, and their high-pitched communications are so ubiquitous that many people mistake them for bird calls.

Many thanks to TreeHugger & the Vermont Wildlife Fact Sheet for the information.