Key takeaways
- Mice can pass through gaps about the size of a dime
- Rats can use quarter-sized openings
- Squirrels need an opening of about two inches
- The Hole Size Checker shows what fits
Wildlife proofing starts with how small an opening can be.
Rules of thumb
Mice fit through gaps near a quarter inch. Rats need about a half inch. Bats can use openings of around three eighths of an inch. Squirrels often use holes of one and a half to two inches, and raccoons can pull open or widen a gap of around four inches.
They make holes bigger
Animals chew, claw and push at an opening until it fits, especially at soft or rotted wood.
Use strong materials
Steel mesh, metal flashing and hard sealants hold up. Foam, plastic and thin screen do not.
Look high and low
Check rooflines, vents, pipe gaps, the foundation and decks. Any one opening can be enough.
Related services
Questions about your own property? Call or text 800-224-9245, or use the estimate form below.