Chipmunks are small, striped rodents common in many residential areas. Their presence is often noticeable due to their industrious burrowing activity, constructing complex, underground tunnel systems for shelter, nesting, and food storage. While not destructive pests like larger burrowing animals, their constant digging can occasionally lead to structural and aesthetic problems in suburban yards. This article examines how to identify a chipmunk’s burrow and assess the risks these tunnels pose to your home and landscaping.
How to Identify a Chipmunk Burrow
The most distinguishing feature of a chipmunk burrow is the entrance, typically a neat, round hole measuring 1.5 to 2.5 inches in diameter. Unlike holes dug by groundhogs or moles, a chipmunk’s entrance lacks a dirt mound or excavated soil surrounding the opening. The chipmunk meticulously carries the loose soil away in its cheek pouches and scatters it elsewhere to conceal the location, making the hole appear clean and inconspicuous.
Entrances are often found in protected locations that provide cover and stability for the tunnel system. Common sites include the base of trees, under piles of rocks or wood, along foundation walls, or beneath shrubs. The tunnels can be extensive, sometimes reaching 20 to 30 feet in length and depths of up to three feet. This complex network includes separate chambers for nesting, drainage, and storing nuts and seeds for the winter.
Assessing the Risk to Structures and Landscaping
The risk chipmunk burrows pose to structures stems from soil displacement beneath paved surfaces and shallow foundations. When chipmunks excavate tunnels under patios, walkways, steps, or retaining walls, they remove supporting soil. This erosion creates voids beneath the surface, which can lead to settling, cracking, or instability of the overlying structure as the weight shifts.
While a single burrow is unlikely to cause catastrophic failure, high population density or continuous tunneling can compromise the integrity of shallow concrete slabs or foundation footings. Water is also a factor, as the tunnels can divert rainwater, potentially leading to excessive moisture accumulation against a home’s foundation or basement.
Damage to the landscape and garden is a more frequent occurrence than structural issues. Chipmunks are omnivores and actively consume newly planted flower bulbs, particularly tulips and crocuses. They also damage vegetable gardens by harvesting seeds, fruits, and young seedlings. Tunneling near mature plants can sometimes sever shallow root systems, which is problematic for young trees or shrubs.
Effective Prevention and Mitigation Strategies
Controlling chipmunk activity involves making the yard less attractive by eliminating food sources and reducing available shelter. Securing or removing bird feeders is a simple habitat modification, as spilled seed is a major attractant. Piles of wood, debris, or rocks near the foundation should be removed, as these offer ideal, protected locations for burrow entrances.
To protect vulnerable garden areas, physical exclusion is highly effective. Flower bulbs can be planted inside wire cages or covered with a layer of 1/4-inch galvanized hardware cloth placed on the soil surface. Near structures, a buried, “L”-shaped barrier of the same hardware cloth can be installed around the perimeter to prevent digging.
Chemical deterrents, such as taste repellents containing Thiram or capsaicin, can be applied to non-edible plants and bulbs to discourage feeding. These repellents require reapplication, especially after rain, to remain effective. If the chipmunk population is high and causing significant damage, live trapping and relocation may be necessary, but property owners must first check local ordinances regarding the legal release of captured wildlife.