Mice in your garage can be removed and prevented with a mix of cleaning, sealing entry points, using traps and deterrents, and removing what attracts them. For lasting results, you need to eliminate access, food, and hiding spots — and keep checking back to make sure they haven't returned.

Remove Food, Water, and Nesting Material

• Take out all garbage, pet food, bird seed, grass seed, or other food. Store in sealed, hard plastic, metal, or glass containers — never in cardboard or bags that mice can chew through.
• Fix any water leaks or standing water — even small drips attract mice.
• Pick up clutter: boxes, stacks of paper, old rags, insulation scraps. Mice use these to build nests.

The #1 Garage Mouse Attractant in NH

Birdseed and grass seed stored in paper or thin plastic bags are the top garage mouse attractant in New Hampshire. Transfer immediately to sealed metal containers or remove from the garage entirely during rodent season (October–March).

Seal Entry Points

The overhead door seal — the rubber strip at the bottom of the garage door — is the primary mouse entry point in most garages. Inspect for gaps: even a 1/4-inch gap is sufficient for a mouse to enter. Replace worn seals immediately.

Also check:

• Gaps around the door frame sides
• The man-door (personnel door) threshold
• Utility penetrations: electrical conduit, gas lines, water pipes

For all gaps: use steel wool combined with caulk to fill holes near the floor, around pipes, vents, and cables. Mice cannot chew through steel wool. Repair window screens and seal around frames.

Trap the Mice Already Inside

• Use snap traps — the most effective option. Bait with peanut butter or chocolate. Place at least 6–10 traps along walls, behind objects, and near droppings or gnaw marks.
• Check traps daily and dispose of dead mice promptly. Wear gloves, use a sealed plastic bag, wash hands after.
• For humane preference, use catch-and-release traps — but release mice at least a mile away.
• Avoid glue traps: inhumane and less effective.

Vehicle Engine Nesting in NH

Mice nesting in vehicle engines — particularly in garage-stored vehicles used infrequently — is a significant risk in NH from October through March. Signs include chewed wiring, nesting material in the engine compartment, and rodent droppings.

Prevention for stored vehicles:

• Leave the hood propped open when the vehicle is stored (reduces warmth that attracts nesting)
• Place snap traps near the tires
• Use engine compartment repellent sachets

Use Mouse Deterrents (Optional)

• Peppermint oil cotton balls or commercial rodent repellent sachets in corners and hiding spots
• Ultrasonic devices are sold for repelling mice but studies show mixed results — not effective for long-term prevention

Keep the Garage Clean and Organized

• Keep storage off the floor and away from walls — use metal or sturdy plastic shelving
• Declutter so mice have fewer hiding places; don't stack boxes along walls or in dark corners
• Regularly sweep and check for droppings, nests, or chewed materials to catch problems early

Long-Term Prevention

• Keep up with sealing, cleaning, and trap checks as a regular routine
• Store all food and potential nesting materials in rodent-proof containers year-round
• Trim plant growth near garage walls and keep the outside perimeter clear — shrubs and debris provide cover for mice seeking entry

When to Call a Professional

If you continue finding mice after following these steps, or see chewed electrical wires or smell strong urine, act quickly. Mice in walls and engine compartments can cause fires and health issues. Call Anchor Pest Services at (603) 785-0118 for a same-day garage inspection across New Hampshire.

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