Fall Pest Prevention: How to Pest-Proof Your Home Before Winter

Fall in Wisconsin is beautiful — and it is the single most important season for pest prevention. As temperatures drop, mice, boxelder bugs, stink bugs, spiders, and cluster flies all look for a warm place to spend the winter. If your home is sealed, they never get in. If it is not, you will be sharing your walls with them until spring.

Here is your DIY fall pest-proofing checklist, ideally done before the first hard frost.

1. Seal Every Exterior Gap — Seriously, Every One

This is the step that matters most. Mice can squeeze through a gap the size of a dime. Walk the entire exterior and seal:

• Cracks in the foundation and around windows and doors.
• Gaps where pipes, vents, and wires enter the home.
• Spaces around the garage door weatherstripping.

Use silicone caulk for small gaps and copper mesh or steel wool stuffed into larger holes before caulking (mice cannot chew through it). This is the core of our pest exclusion service, and you can do most of it yourself.

2. Install or Replace Door Sweeps

A gap under an exterior door is the easiest way in for mice and insects. Make sure every exterior door — including the one to the garage — has a door sweep that seals flush to the threshold with no daylight showing.

3. Clean Out the Gutters

Clogged gutters overflow and soak the soil next to your foundation, which attracts moisture-loving pests and can even draw termites. Clean gutters in fall and make sure downspouts carry water well away from the house.

4. Move Firewood Away

Firewood stacked against the house is a five-star hotel for mice, spiders, and overwintering insects. Move any woodpile at least 20 feet from the home and store it off the ground.

5. Rake Leaves Away From the Foundation

A thick mat of wet leaves against the foundation holds moisture and shelters pests all winter. Rake a clear 12-inch border around the home and bag the leaves.

6. Check the Attic and Vents

Squirrels, raccoons, and bats look for attic entry points in fall. Make sure all vents are screened and intact, and look for any new gaps in the roofline or soffits. Humane exclusion now is far easier than dealing with a wildlife problem in January — see our wildlife control page.

7. Screen the Chimney

If you have a chimney, make sure the cap and screen are intact. Birds, squirrels, and bats all use uncapped chimneys to get inside.

8. Manage Overwintering Bugs

Boxelder bugs, stink bugs, and Asian lady beetles cluster on sunny south- and west-facing walls in fall, then crawl inside to wait out the winter. The only real fix is exclusion — if they cannot get in, they cannot stay. Use our pest identifier to confirm what you are seeing, and learn more about why boxelder bugs invade Wisconsin homes every fall.

9. Do a Kitchen Deep Clean

Mice that do get in will head straight for the kitchen. Preempt them by deep-cleaning the pantry, storing all food in sealed containers, and removing any clutter that could serve as nesting material.

When Fall DIY Becomes a Winter Problem

If you hear scratching in the walls or attic, see droppings, or find insects gathering at windows through the winter, you already have tenants. Do not wait — our emergency wildlife removal and humane exclusion services can solve it before it gets worse. Request a free inspection and we will help you close the gaps for good.