Chipmunks are small, striped members of the ground squirrel family whose tunneling can quickly become a serious nuisance for property owners. These active rodents create extensive underground networks that can compromise structural integrity and ruin landscapes. While a single chipmunk might seem harmless, a population can cause damage by undermining structures like patios, sidewalks, and home foundations. Addressing these tunnels requires a strategic approach, starting with making your property less attractive and moving to physical removal if necessary.
Identifying Chipmunk Burrows and Damage
Identifying a chipmunk burrow is the first step in effective management, as their tunnels differ significantly from those made by moles or voles. The most distinctive feature of a chipmunk entrance is its clean, unadorned opening, typically one to two inches in diameter. Unlike other burrowing pests, chipmunks meticulously carry the excavated soil away in their cheek pouches, preventing the formation of a visible dirt mound or “volcano.”
These entrances are frequently located near protective cover, such as beneath dense shrubs, woodpiles, or alongside permanent structures like retaining walls and building foundations. The tunnel systems themselves can be quite complex, extending up to 30 feet in length and reaching depths of three feet underground. This extensive digging causes structural damage by removing supporting soil, leading to the sinking or cracking of concrete slabs, walkways, and patio stones. In garden beds, tunneling disturbs root systems, and the chipmunks’ habit of hoarding food means they often dig up and consume flower bulbs and seeds.
Exclusion and Habitat Modification
The most sustainable method for controlling chipmunk activity involves making the surrounding habitat physically inaccessible and removing primary attractants. Since chipmunks are heavily drawn to readily available food, securing or eliminating these sources is an immediate step. Spilled bird seed, especially from feeders, is a major culprit; switching to less appealing seeds like safflower or Nyjer can reduce foraging interest. All outdoor pet food and garbage should also be secured in containers with tight-fitting lids.
Physical barriers offer a permanent solution to prevent burrowing near vulnerable structures. For areas like sheds, decks, and foundations, installing a subterranean fence made of galvanized 1/4-inch hardware cloth is highly effective. The mesh must be buried at least six to twelve inches deep and then bent outward at a 90-degree angle for an additional twelve to eighteen inches to create an “L-shaped” apron. This outward-facing flange deters chipmunks from digging directly down next to the barrier. Before completely sealing the final entrance point, confirm all animals have evacuated, often by installing a one-way exclusion door.
Non-Lethal Repellent Strategies
When physical exclusion is impractical, non-lethal repellents can be used to make an area unappealing to chipmunks through sensory irritation. Repellents based on capsaicin, the compound that gives chili peppers their heat, deter chipmunks by causing an unpleasant burning sensation when they taste or touch it. These products are sprayed onto plants, bulbs, or soil and are often mixed with a sticking agent like liquid soap to help the solution adhere to surfaces.
Another effective deterrent utilizes the chipmunk’s instinctual fear of predators. Commercial repellents containing the urine scent of natural predators, such as fox or coyote, signal danger to the chipmunks, encouraging them to relocate. This type of repellent is most successful when applied in scent stations or on cotton balls placed near high-activity areas like burrow entrances. Since all topical and scent-based repellents degrade, reapplication is necessary, particularly after rain or heavy watering.
Trapping and Physical Removal
When preventative and repellent methods fail to control an established population, trapping and physical removal may become necessary. Small wire cage traps, designed specifically for rodents, are the preferred method for live capture. These traps should be baited with a highly attractive food that cannot be easily stolen, such as a sticky mixture of peanut butter and oatmeal or sunflower seeds. Placing a small amount of bait outside the trap and a larger portion behind the trigger plate encourages the chipmunk to fully enter.
For the best results, the trap should be positioned along known travel routes, such as parallel to a fence line or adjacent to a burrow entrance. A technique called pre-baiting, where the trap door is wired open for a few days, can increase the animal’s confidence before the trap is set. Before relocating a captured chipmunk, check local and state regulations, as transporting wildlife is often restricted due to concerns about disease spread and low survival rates.
If lethal control is chosen as a last resort for severe infestations, rat-sized snap traps are widely used due to their effectiveness. For safety, the trap trigger should be baited with a sticky item like peanut butter and oats to prevent theft. These traps must be placed in a protective cover, such as an inverted box with a small entrance hole, to shield them from pets and non-target wildlife. Placing the trap perpendicular to a wall or structure along a travel path increases the chances of a successful and quick capture.