Both squirrels and chipmunks belong to the same family of rodents, which also includes marmots and prairie dogs. There are many different species of squirrel, but they can be grouped into three main types: ground, tree, and flying. The latter two are quite distinct from chipmunks, but ground squirrels are very similar in their appearance and habits, and it can be argued that chipmunks are simply a type of ground squirrel. The main distinguishing features are that chipmunks are generally smaller and have stripes on their faces.
While squirrels are found all over the planet, except for the polar regions, chipmunks are confined to North America, apart from one species found in northeast Asia. They have, however, been introduced into a few other areas. In places where both animals are present, it may sometimes be difficult to tell certain species apart.
Appearance
Like other rodents, both of these animals have four sharp incisors, used for gnawing, and flat back teeth, used for grinding hard food like nuts. They typically have four toes on each front foot, and five on each back foot. In areas where both are found, chipmunks are smaller, typically weighing only 2 to 4 ounces (56.7 to 113.4 grams), but a young ground squirrel could easily be mistaken for an adult chipmunk. In terms of color, both are quite variable. Chipmunks always have stripes, and while this is also true of many ground squirrels, they differ in that the stripes do not extend onto the face.
Habits and Behavior
These two types of rodent tend to prefer different habitats, although there is some overlap. Chipmunks are mostly found in forested areas, where they can find trees and bushes that provide fruit, nuts and seeds. Ground squirrels, however, like to live in grassy areas, which why they are often seen in parks and golf courses. The animals differ also in their burrows. A squirrel’s burrow can be identified by the mound of earth at its entrance, while a chipmunk’s is clear of all dirt and is usually located at the base of a tree or bush.
A chipmunk also has pouches inside its cheeks, which it uses for storing food while foraging. The puffed-out cheeks may be quite visible, but are not a reliable identifying feature, as some ground squirrels also have them. A clearer difference is that chipmunks tend to hold their tails straight in the air while running, while a squirrel runs with its tail at a horizontal angle.
Both types of animal hibernate, but the two differ in the way they store food and prepare for the winter. A squirrel will eat more as winter approaches, in order to build up its body mass enough to sustain it through the long, cold months, whereas a chipmunk eats food stored in its pouches as well as in and around its burrow during that time. Squirrels tend to have multiple food stores, and they may briefly emerge during the winter to feed on days when conditions are not too harsh.
Relationship with Humans
Both animals can be useful to humans in that they include insects in their diets and help keep numbers down. They can also, however, be quite troublesome. Squirrels in particular may cause damage to gardens by digging up bulbs, eating buds and shoots, and stripping bark from trees to use as nesting material. They will often raid bird food, sometimes showing great ingenuity in getting into feeders despite efforts to deter them. They may also venture into homes and sometimes build nests in lofts and attics. Chipmunks tend to be less destructive, but they may eat seeds and bulbs and sometimes enter homes.
There are a number of humane options for dealing with problems caused by these animals. Entry into the home can be prevented by screening windows and blocking any holes or gaps that might allow access to a loft or other part of the house. The rodents can also be caught using commercially available traps, to be released in another area. Dried blood and the urine of predators, such as foxes and coyotes, may also have a deterrent effect.