Why fall?
As temperatures drop in September and October, mice look for warm, sheltered places with food nearby. Sealing your home before the first frost is far easier than removing mice that have already settled in.
The outside checklist
- Garage door sweep. Replace a worn or torn bottom seal; check the corners where gaps hide.
- Utility lines. Seal gaps where gas, water, cable and A/C lines enter the house.
- Dryer and exhaust vents. Make sure flaps close fully; add a rodent guard if needed.
- Foundation cracks. Seal cracks and gaps around basement windows.
- Weep vents. Use proper weep vent covers rather than blocking them, so the wall can still drain.
- Roof and soffit gaps. Mice climb. Check where the roof meets the soffit.
- Firewood and debris. Store firewood off the ground and away from the house.
- Vegetation. Trim shrubs and ivy back from the walls.
The inside checklist
- Store food, pet food and birdseed in sealed containers.
- Clear clutter from the garage, basement and storage rooms.
- Look for droppings behind appliances and under sinks.
- Seal gaps under sinks where pipes go through the wall.
What to seal gaps with
Mice chew through foam and soft plastic. Use steel wool or copper mesh packed into the gap and sealed with caulk, or metal flashing and hardware cloth for larger openings.
When to call a professional
If you hear scratching in walls, find droppings in more than one room, or see mice during the day, they are already inside. A rodent program removes the population and seals the entry points they are using.