Reviewed by William "Willy" Vizcarrondo, NYS DEC Certified Commercial Pesticide Applicator C1825832. Updated September 23, 2026.
Short answer
Because the garage is the easiest room to get into. A garage door that doesn't seal at the corners is a gap a mouse walks through, and birdseed, pet food, cardboard and clutter inside make it a place to stay. Yes, they get into the house next: the door and the wall between garage and kitchen are the most common route we find.
The CDC lists the garage door and the gaps around it among the standard rodent entry points, and on most houses it's the biggest opening on the building: a worn bottom seal, a bent track, a gap at each corner where the rubber doesn't meet the concrete. A mouse needs a quarter inch. Inside, the garage has everything: birdseed, grass seed and pet food in the original bags, cardboard boxes to nest in, a car engine that's warm for an hour after you park, and a wall shared with the kitchen that's full of pipes and wires.
Through the wall and the door. The door from the garage into the house usually has a threshold gap or a worn sweep, and the wall between garage and kitchen carries plumbing, electrical and the dryer vent, each with a hole around it that was never sealed. Mice follow those lines into the kitchen cabinets and the basement ceiling. UC IPM notes they seldom travel more than 30 feet from nest to food, and a nest in the garage ceiling with a pantry on the other side of the wall is well inside that range.
Seal the garage door first: new bottom weatherstrip, corner seals or brush seals at the sides, and steel wool or hardware cloth in any gap where the frame meets the foundation. Then the interior: a door sweep on the door into the house, and steel wool and caulk or metal around every pipe, wire and vent through the shared wall. Move birdseed, grass seed and pet food into metal or heavy plastic bins with lids, get the cardboard off the floor and into plastic totes, and set traps along the garage walls and behind stored items. Then trap the house side.
The attached garage is why the postwar towns have the mouse problem they do. Levittown, East Meadow, Centereach, Holbrook and Deer Park are block after block of capes, ranches and high-ranches with a garage on the kitchen, and the mice come in under the garage door the first cold week of October and are in the cabinets by November. Sealing the garage door is the single highest-value thing a Long Island homeowner can do before fall.
Related
Take away the food and the shelter around it. Mice in a car are usually nesting in the engine bay or the cabin air filter box because the garage is infested, so the fix is the garage: seal the door, move the birdseed and pet food into sealed bins, set traps along the walls, and check the engine bay and filter box for nesting.
They can, if there's food. A garage with an open bag of birdseed or dog food is a year-round home, not a winter one. Without food, mice pass through the garage on the way to the house in fall, which is why the garage is where the traps and the sealing go first.
Both, starting in the garage. Traps along the garage walls, behind stored items and near the door into the house catch mice on the route in. Traps in the kitchen cabinets and basement catch the ones already inside. Seal the garage door and the shared wall the same day you set them.
Still not sure? Call (516) 509-6001 and we'll tell you what you're dealing with.