**Chipmunks** are small, striped rodents belonging to the genus *Tamias* (Eastern chipmunk) or *Neotamias* (Western chipmunks). They are recognized by the prominent dark and light stripes that run down their backs and sides. While highly charismatic and generally harmless, they can become structural and garden pests by burrowing under patios, foundations, and sidewalks, and by consuming seeds, bulbs, and young seedlings.
Taxonomy and Classification
Chipmunks are members of the family Sciuridae (squirrels, marmots, and prairie dogs) in the order Rodentia. The Eastern Chipmunk (*Tamias striatus*) is the single species found in eastern North America, while the genus *Neotamias* encompasses over 20 species in the western part of the continent. They are true mammals and are characterized by their specialized teeth adapted for gnawing and their highly developed cheek pouches for carrying food.
Physical Description
Chipmunks are small, usually 5–10 inches long (including the tail). Their most distinguishing features are the five dark, longitudinal stripes running down their back and sides, separated by light-colored stripes. Their coloration is typically reddish-brown to grayish-brown. They are quick, agile, and possess large cheek pouches that, when full, can make their heads appear disproportionately large.
They are often confused with ground squirrels, but chipmunks are smaller, have stripes that extend to their head, and often climb trees and shrubs more readily than ground squirrels.
Distribution and Habitat
Chipmunks are found throughout most of North America, from southern Canada to Mexico. They thrive in woodland and shrubland habitats but readily adapt to suburban and urban areas, especially those with rock walls, woodpiles, or thick ground cover. Their habitat is closely tied to their burrow system, which they dig in the ground, often hidden beneath logs, stones, or landscape features like porches and foundation slabs.
Behavior and Life Cycle
Chipmunks are solitary, diurnal (active during the day) animals. They are active throughout the spring, summer, and fall, spending the winter in their burrows in a state of torpor (not true hibernation), waking occasionally to feed on their stored caches. Their burrow system can be extensive, with tunnels that may be 20–30 feet long, containing multiple chambers for nesting and food storage, and lacking a conspicuous entrance mound.
They typically mate twice a year, once in the early spring and again in early summer, producing litters of 2–8 young. They spend their active hours foraging, stuffing their cheek pouches with food, and carrying it back to their caches.
Feeding and Damage
Chipmunks are **omnivores**. Their diet consists mainly of nuts, seeds, berries, fungi, insects, bird eggs, and occasionally small vertebrates. In gardens, they can be highly destructive by digging up and consuming newly planted seeds (corn, sunflower), bulbs (especially tulips and crocuses), young vegetable seedlings, and soft fruits like strawberries.
The most serious damage to homes is structural: their extensive burrow systems, when excavated beneath concrete slabs, patios, retaining walls, or foundations, can undermine the stability of these structures, leading to shifting or cracking. They also sometimes nest in attics or wall voids, causing minor damage to insulation.
Management and Prevention
Control focuses on **exclusion and habitat modification**. Prevention involves:
- Eliminating Shelter: Remove wood piles, rock piles, and dense shrubs close to the foundation.
- Securing Food: Clean up fallen birdseed (a major attractant) and secure garbage and pet food. Use bird feeders designed to be squirrel/chipmunk proof.
- Exclusion: Seal all foundation cracks and openings into the structure. If burrows are under a foundation, the burrows can be filled after the chipmunks are removed, and a wire mesh barrier can be buried vertically (at least 12 inches deep) to discourage redigging.
- Repellents/Trapping: Commercial repellents often have limited success. In cases of structural damage, live trapping and relocation (where permitted) or lethal trapping may be the only effective long-term solution.
Conservation and Research
Chipmunks are not typically endangered and are often abundant. Research focuses on their role in seed dispersal and forest regeneration, as well as the unique behavioral differences between the numerous species of Western chipmunks.