Chipmunks are small rodents whose extensive burrowing systems can damage landscapes and structures. They dig primarily to create food caches and sheltered nesting areas, often choosing locations near patios, foundations, or retaining walls for structural support. Preventing this damage requires an integrated strategy focused on making the environment physically inaccessible and unattractive. This involves structural exclusion, habitat modification, and remediation of existing tunnels.
Blocking Access with Physical Barriers
Physical barriers offer the most reliable long-term solution for preventing chipmunk digging, especially around vulnerable structures like foundations and decks. The most effective method is installing a subterranean barrier, or apron, made from galvanized hardware cloth with openings no larger than one-quarter inch.
To create this barrier, dig a trench around the perimeter of the area you wish to protect. The mesh should be buried six to twelve inches deep and bent outward in an L-shape, extending horizontally away from the structure for another twelve to eighteen inches. This apron prevents the chipmunk from digging straight down beneath the obstruction. For garden beds, secure the one-quarter inch mesh underneath the structure’s base or lay it over the soil during bulb planting. Gaps beneath decks and porches should be fully skirted with this chew-resistant mesh to eliminate easy access to sheltered burrowing spots.
Using Environmental and Sensory Deterrents
Making the immediate environment less appealing complements physical exclusion methods. Eliminating easily accessible food sources is a primary form of habitat modification. Spilled birdseed is a major attractant and should be cleaned up immediately, or feeders should be moved at least fifteen feet away from structures. Removing dense ground cover, rock piles, and brush piles near the home also removes secure hiding and nesting locations, forcing chipmunks to seek shelter elsewhere.
Sensory repellents can create a chemical fear response or a taste aversion, though their effectiveness is temporary. Predator urine, typically from foxes or coyotes, is an olfactory deterrent that triggers a survival instinct. These products are applied as a perimeter barrier and must be reapplied frequently, especially after rainfall. Taste repellents containing capsaicin, derived from chili peppers, can be applied to bulbs or non-edible plants to discourage chewing and foraging. Motion-activated sprinklers provide a sudden burst of water that can momentarily deter chipmunks from entering a specific area.
Sealing and Monitoring Existing Burrows
Dealing with existing holes requires careful monitoring to ensure no chipmunk is trapped inside. To determine if a burrow is currently active, lightly cover the entrance with loose soil, crumpled leaves, or flour. If the material is disturbed within twenty-four to forty-eight hours, the tunnel is still in use, and sealing should be postponed until activity ceases.
Once a burrow is confirmed inactive, it can be sealed using materials that resist re-excavation. A mixture of gravel and soil packed firmly into the hole creates a barrier difficult for a chipmunk to penetrate. For burrows adjacent to concrete foundations or walkways, a cement patch may be necessary to ensure structural integrity and a permanent seal. After filling, the area must be monitored for several days, as the chipmunk may simply dig a new exit hole nearby if it was still using the tunnel.