How to Deter Chipmunks From Your Home | Exclusion That Works

Chipmunks chew through siding, dig under foundations, and nest in crawl spaces, and once they find a gap, they keep coming back. The fixing approach that actually works is straightforward: block every opening they can squeeze through, then remove what draws them in. Repellents and noise devices rarely change the outcome. Here’s how to build a chipmunk-proof line around your home, starting with the entry points that matter most.

Seal The Entry Points First

Exclusion is the single most reliable chipmunk deterrent, and it starts with the 1/4-inch mesh that wildlife experts consistently recommend. Kansas State Extension advises sealing openings with 1/4-inch (0.6-cm) hardware cloth or welded wire, plus caulking around gaps. A chipmunk can fit through surprisingly small holes, so 1/4-inch mesh is the standard that keeps them out.

Walk your foundation and look for these specific trouble spots:

• Utility penetrations — gaps where gas lines, water pipes, electrical conduit, or cable enter the house. Stuff these with copper mesh or hardware cloth, then seal the edges.
• Vents — cover foundation vents, attic vents, and dryer vents with 1/4-inch welded wire or screening.
• Gutters and downspouts — the Integrated Crop Management site notes that gutter guards and covered downspouts prevent chipmunk entry, and that “no frightening devices are effective” against them.
• Under-structure areas — fit welded wire barriers under decks, porches, sheds, patios, and crawl spaces so chipmunks can’t burrow beneath them.

Remove What Attracts Them

Chipmunks stay where food and cover are easy, so removing both changes the math. Keep bird seed, pet food, flower seed, and vegetable seed in sealed metal or plastic containers — never open bags in a garage or shed. If bird feeders are up, place them where chipmunks can’t leap to them, and keep the ground underneath raked clean of fallen seed.

Cover matters just as much. Don’t stack firewood against the building, and trim back landscaping that forms a continuous path from wooded areas to your foundation. Brush, rock, and wood piles near the structure give chipmunks safe routes and nesting spots, so clear them away from the house line.

Why Repellents And Mothballs Fall Short

You’ll see mothballs, naphthalene flakes, ultrasonic devices, and granular repellents marketed for chipmunks, but the evidence is thin. The Missouri Department of Conservation says mothballs are ineffective and that naphthalene vapors are harmful to humans. Kansas State Extension adds that naphthalene flakes may irritate people or pets in occupied buildings. The University of Georgia Extension states there are no registered repellents for chipmunks at all.

Frightening devices don’t fare better. The ICWDM’s guidance is blunt: no frightening device is effective for chipmunk control. Skip the ultrasonic plugs and motion-sensor sprinklers as a primary plan. If you do try a granular repellent, check for an EPA label that lists chipmunks as a target species, and use it strictly outdoors away from children and pets. It’s a possible aid, not a solution.

Use Traps Only As A Last Resort

When exclusion and cleanup aren’t enough — say, for a heavy burrow infestation — trapping is the fallback. The University of Georgia Extension advises setting traps along runways and near burrow openings, in outdoor areas protected from children and pets. Follow your state’s wildlife rules on trap type and release, since regulations vary by location.

Trapping is a spot fix, though. If gaps remain open, new chipmunks move in behind the ones you remove. That’s why sealing the foundation first is the order that works. If you want help choosing a deterrent product that fits your situation, our tested roundup of the best chipmunk deterrent options breaks down what’s worth buying and what isn’t.