Fall Pest-Proofing Checklist for Central Ohio Homes

Why does fall bring pests inside?

When nights cool, mice, stink bugs, boxelder bugs and lady beetles all go looking for a warm, protected spot. Your house has plenty of them: wall voids, attic corners, gaps by the garage door. They do not need much room to get in.

Columbus Public Health points to Columbus Health Code §221.03, which says openings of half an inch or more within 48 inches of ground level should be sealed. Mice can fit through gaps smaller than that, so treat the half inch as a ceiling, not a target. Start with anything you can slide a finger into.

What goes on a fall pest-proofing checklist?

Work from the outside in, and do the ground-level items first, since mice use them.

1. Walk the foundation. Look for cracks, gaps around pipes and cable lines, and missing mortar. Seal with caulk for small gaps and a metal or mesh filler for larger ones.
2. Replace door sweeps and weatherstripping. If you can see daylight under an exterior door, a mouse can use it. Check the garage door seal as well.
3. Screen the vents. Dryer vents, attic vents, crawl space vents and chimney openings should have intact screens or caps.
4. Check windows. Repair torn screens and gaps at frames. Insects often enter at the top of south-facing windows, where the sun warms the wall.
5. Move firewood and clutter. Stack firewood away from the house and off the ground. Pull piles of boards, leaves and mulch back from the foundation.
6. Clean the gutters. Standing water and debris draw insects and rot wood.
7. Tidy the garage and basement. Store food, pet food and birdseed in sealed bins, and lift cardboard off the floor.
8. Look at the roofline. Check where the fascia, soffit and siding meet for gaps that lead to the attic.

Which material fits which gap?

The wrong filler is the most common reason a seal fails. Match the material to the opening:

Should window air conditioners come out in fall?

Yes. Ohio State University Extension advises removing window air conditioners in fall, since their narrow vents attract stink bugs. Pull the unit, seal the gap around the window frame and vacuum any bugs on the sill. Cover or store the unit so nothing nests in it over winter.

Which fall pests should you watch for in central Ohio?

What is the right order for fall pest-proofing jobs?

Timing matters as much as the list. Central Ohio averages about 53°F across the year (NOAA climate normals), so the first hard cold can arrive while the leaves are still on the trees. Pace the work like this:

• Early fall: clean gutters, check the roofline and screens, and move firewood off the wall.
• Before the first cold snap: caulk, replace door sweeps and seal the foundation on a dry day.
• After the first frost: check the garage, basement and attic access for droppings or new activity, and set traps if you find signs.
• Mid-winter: look again at the places you sealed, because settling and freezing can open new cracks.

Doing the roofline first is deliberate. Stink bugs and boxelder bugs gather on warm, sunny walls in early fall, and a sealed upper wall keeps them out before they find the gap.

Can you seal everything yourself?

A lot of it, yes. Caulk, weatherstripping and screens are inexpensive hardware-store jobs. The parts that tend to defeat homeowners are the ones you cannot reach or see: roofline gaps two stories up, openings behind siding and the chase where a pipe enters a wall.

That is where pest exclusion and sealing work comes in. Exclusion means closing the openings pests use so they cannot return. For rodents specifically, see our rodent proofing service. If you already hear scratching, sealing alone traps animals inside, so call before you plug anything.

What if you rent and cannot seal the building?

You can still do the inside half. Store food in sealed containers, keep cardboard off the floor and vacuum insects off windowsills. About 56% of Columbus homes are renter-occupied (ACS 2019-23), so this is a common problem across Columbus.

The outside half belongs to the owner. For a multi-unit building, Columbus Public Health says eliminating pests is the owner's duty. Tell the landlord in writing, list the gaps you see with dated photos and keep a copy. Do not caulk or drill structural openings in a rental yourself unless the lease allows it.

What should you do about pests that are already inside?

Sealing keeps new arrivals out, but it does not remove the ones already in the walls. Droppings, gnawed packaging and a steady trickle of bugs on a window mean the work needs to start indoors as well. Our mouse control and stink bug control pages explain how those jobs go.

Avoid foggers and bug bombs. They rarely reach the voids where pests hide, and they can push insects deeper into the walls.