Chipmunks are small rodents that become pests when they seek shelter and food near human dwellings, often resulting in damage to foundations, flower beds, and gardens. Effectively deterring chipmunks requires a multi-pronged approach that makes an area fundamentally less inviting. This involves removing the resources attracting them, applying sensory deterrents, and physically modifying the habitat to block access.
Identifying and Removing Key Attractants
The first step in chipmunk deterrence is eliminating the resources that draw them to a property. Chipmunks are attracted to easy-to-access food sources, which they collect and cache. Common culprits include spilled seed from bird feeders, pet food left outdoors, and fallen nuts or fruit.
They are also fond of planting materials like flower bulbs, which they will dig up and consume. Moving bird feeders at least 15 feet away from the home and sealing all pet food and stored seeds in secure containers can significantly reduce foraging opportunities. A clean yard, free of debris, is naturally less appealing, as it offers fewer hidden food stashes.
Chipmunks seek out secure, easily concealable locations for their elaborate burrow systems. Areas providing shelter include dense ground cover, stacked firewood, rock walls, and piles of debris. Eliminating these hiding spots forces the chipmunk to search for shelter elsewhere, making the property less desirable for nesting. Minimizing dense landscaping near the house foundation also removes protective cover that allows them to hide burrow entrances.
Utilizing Sensory Repellents
Chipmunks rely on their keen sense of smell and taste, which can be exploited using repellents. These deterrents work by creating an odor or flavor the chipmunk perceives as unpleasant. Many commercial repellents contain capsaicin, the compound that gives chili peppers their heat, which creates an irritating sensation when tasted or smelled.
Granular or liquid repellents containing bittering agents like Bitrex or Thiram are also effective when applied to bulbs and foliage not intended for human consumption. These substances make the treated plant material taste foul without causing harm. Application needs to be consistent, with reapplication necessary after heavy rain or watering to maintain effectiveness.
Other deterrents utilize strong natural scents, such as peppermint, eucalyptus, or garlic, which overwhelm the chipmunk’s olfactory senses. The scent of predator urine, such as fox or coyote, can also trigger an innate fear response, making the area feel unsafe. These materials should be applied around burrow entrances and along property perimeters to establish an olfactory barrier.
Exclusion and Habitat Modification
Physical exclusion methods provide a long-term solution by blocking access to vulnerable areas and nesting sites. Because of their small size, a fine mesh barrier is required; galvanized hardware cloth with a quarter-inch mesh size is recommended to prevent entry. This mesh can be used to seal any openings in the foundation, shed, or deck where chipmunks might enter a structure.
To protect garden beds and prevent burrowing near foundations, the hardware cloth barrier should be buried vertically into the ground. A depth of 6 to 12 inches is sufficient, often installed in an “L”-shape extending outward to discourage digging underneath the barrier. For individual bulbs, planting them within a small cage or covering them with a flat layer of hardware cloth before covering with soil prevents them from being dug up.
Motion-activated deterrents utilize sudden action to startle the animals. Devices like motion-activated sprinklers use an infrared sensor to detect movement, triggering a sudden, harmless burst of water. This unexpected spray, noise, and movement conditions the chipmunk to avoid the protected area over time. Ultrasonic devices that emit high-frequency sound waves may also be used, although their effectiveness can vary.