Chipmunks are small, striped rodents commonly seen darting across forest floors and suburban yards, often with their cheek pouches bulging from foraging trips. They spend a significant portion of their lives beneath the surface, where they establish their homes. Understanding where these animals make their nests means looking to the subterranean architecture they construct for survival. Their nesting habits are tied directly to their need for safety, food storage, and shelter during the colder months.
The Essential Underground Home
Chipmunks make their permanent residences almost exclusively underground, creating elaborate burrows that serve as their year-round habitat. The chipmunk burrow is a fixed dwelling used for resting, raising young, and surviving the winter period of torpor. Foraging occurs above ground, but the subterranean network provides a secure retreat from predators and environmental extremes.
The entrance to this extensive tunnel system is a small, neat hole, usually measuring about two inches in diameter. This opening leads to an underground complex that can be quite spacious, with tunnels extending up to 30 feet in length and reaching depths of three feet below the surface.
The burrow’s depth provides a stable temperature environment, offering insulation from both summer heat and winter cold. This structure provides the necessary security for the six weeks that the young remain underground before venturing out.
Anatomy of the Burrow: Chambers and Nesting Materials
The internal architecture of a chipmunk burrow is highly specialized, consisting of a main tunnel system that connects various dedicated chambers. The tunnel network often runs alongside tree roots, which can provide structural support.
The most important space is the nesting chamber, where the chipmunk sleeps and raises its litter. This chamber is typically centrally located and is larger than the tunnels, measuring approximately six to ten inches in diameter. To ensure warmth and comfort, the chipmunk lines this area with soft, insulating materials like shredded leaves, dried grasses, and fine plant fibers gathered from the surface.
Beyond the nesting area, the burrow includes several other specialized compartments. Storage chambers, sometimes called food galleries, are used to hoard provisions collected during the warmer months, providing the food source for the chipmunk during its winter period of torpor. Some burrows also feature narrow drainage tunnels that extend downward to mitigate the risk of flooding in the main living areas.
Preferred Above-Ground Starting Points
Chipmunks exhibit a strong preference for locating their burrow entrances in spots that offer both cover and structural stability for the tunnels. They seek out environmental features that help conceal the opening from predators. Common starting points include areas hidden by dense shrubbery, beneath a pile of rocks, or near the base of old logs and fallen trees.
In suburban environments, chipmunks frequently take advantage of man-made structures to provide necessary cover and support. They often excavate their burrows near or under building foundations, beneath decks, or alongside patios and stone walls. This proximity helps stabilize the earth around the tunnel system.
A key characteristic of a chipmunk burrow is the absence of a visible mound of excavated dirt at the entrance. As the chipmunk digs, it meticulously carries the excess soil away from the entrance in its cheek pouches. This behavior ensures the entrance remains discreet and inconspicuous.