Winterproofing Your Home or Business Against Rodents

Table of Contents

• Key Points
• Why Rodents Move Indoors During the Winter
• Common Rodents That Invade Upstate Homes and Businesses
• Where Rodents Get Inside
• What Is Rodent Exclusion?
• Winter Proofing Steps You Can Take Now
• Pest Proofing for Businesses
• When to Call a Professional
• Rodent Exclusion and Winter Proofing From Precision Pest and Wildlife Removal
• Frequently Asked Questions
• References

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Key Points

• During cold weather, rodents seek warm, sheltered spaces, which makes late fall and winter a prime time for mice, rats, and squirrels to move indoors.
• Rodent exclusion—the work of finding and sealing the openings rodents use to get inside—is the foundation of lasting winter proofing and pest control.
• Simple steps can help between professional visits, but rooflines, attics, and active squirrel problems are best handled by a trained professional.

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According to the U.S. Census Bureau, almost 15 million homes in the United States report seeing rodents in the previous year.¹ Mice, rats, and squirrels are not looking for trouble so much as shelter, food, and a dependable source of water, and a typical house or commercial building can offer all three.

The good news is that most rodent problems can be identified and addressed. That is the core idea behind rodent exclusion, and it is one of the most important parts of winter proofing any property. Below, we explain why rodents move indoors during the colder months, which species are most likely to show up, where they get in, and what you can do now to keep them out.

Why Rodents Move Indoors During the Winter

Mice and rats do not hibernate. They remain active through the winter, and as outdoor food sources thin out and nighttime temperatures drop, the inside of a wall, attic, or crawl space becomes an attractive place to nest. Squirrels follow a similar pattern, often using attics, soffits, and chimneys as sheltered den sites. Winters in the Upstate are milder than in much of the country, but a stretch of cold nights is usually enough to send rodents looking for a way inside.

Once indoors, rodents can create problems that go well beyond the occasional sighting. These include:

• Property damage: Rodents gnaw constantly to keep their teeth worn down, and they will chew through wood, drywall, insulation, and plastic piping.
• Fire risk: Chewed electrical wiring in attics and wall voids can create a genuine fire hazard.
• Contamination: Droppings and urine can contaminate food, stored goods, and surfaces, and rodents are known to carry dozens of diseases.²
• Insulation damage: Nesting rodents tunnel through, compress, and soil attic insulation, which can reduce its effectiveness and raise energy costs.

Common Rodents That Invade Upstate Homes and Businesses

The term “rodent” covers more than mice and rats. In Greenville and the surrounding Upstate counties, property owners most often deal with the following species:

• House mice: Small, prolific, and comfortable living alongside people, house mice often nest inside walls, cabinets, appliances, and stored boxes.
• Norway rats: Larger, heavier rodents that tend to burrow along foundations and enter at ground level through crawl spaces, drains, and gaps around pipes.
• Roof rats: Agile climbers that favor upper levels, roof rats often reach rooflines, soffits, and attic vents by way of overhanging branches or utility lines.
• Eastern gray squirrels: Active during the day, gray squirrels can chew openings into fascia boards, soffits, and roof vents, and they frequently set up dens in attics.
• Southern flying squirrels: Small, nocturnal, and social, flying squirrels can enter through an opening about the size of a quarter and are often heard moving through attics at night.
• Other rodents: Chipmunks and moles usually stay outdoors, but their burrowing near foundations, walkways, and planting beds can still cause problems around a property.

Where Rodents Get Inside

Rodents can use openings at nearly every level of a building, from the foundation to the roof. The most common entry points include:

• Rooflines and soffits: Gaps where the roof meets the fascia, loose soffit panels, and openings at the eaves give climbing rodents easy access to the attic.
• Gable and attic vents: Vents with damaged or missing screens are a frequent entry point for squirrels and roof rats.
• Chimneys: An uncapped chimney can serve as an open door for squirrels and other wildlife.
• Utility penetrations: The openings around electrical, plumbing, cable, gas, and HVAC lines are often larger than the lines themselves.
• Foundations and crawl spaces: Foundation cracks, gaps between the foundation and the ground, and unscreened crawl space vents invite ground-level rodents.
• Doors and garage doors: Worn weatherstripping and missing door sweeps can leave gaps along the bottom of exterior and garage doors.
• Dryer and exhaust vents: Vents without proper covers can give rodents a direct path into the living space.

What Is Rodent Exclusion?

Rodent exclusion is the process of physically keeping rodents out of a building by locating and sealing the openings they use to get inside. Traps and bait stations can reduce the number of rodents already present, but they do not address how those rodents got in. Without exclusion, new animals tend to find the same openings, and the cycle repeats.

The Centers for Disease Control and Prevention (CDC) places sealing entry points at the center of its rodent prevention guidance, noting that a mouse can fit through a hole about the size of a pencil, roughly one-quarter inch across.³ That is why effective pest proofing depends on a careful, methodical inspection and attention. 

Winter Proofing Steps You Can Take Now

A professional inspection is the most reliable way to find every opening, but there is plenty you can do between visits to make your property less inviting. Here are a few practical steps:

• Seal small gaps: Pack small holes with steel wool and hold it in place with caulk, since steel wool is difficult for rodents to chew through.
• Cover larger openings: Use hardware cloth, metal flashing, or sheet metal for larger gaps, particularly around pipes and vents.
• Replace door sweeps and weatherstripping: Update worn seals on exterior doors and garage doors so that no daylight shows along the bottom edge.
• Cap and screen: Add a chimney cap and repair or replace damaged vent screens.
• Trim trees and shrubs: Cut limbs back at least 10 feet from the roofline to keep squirrels and roof rats from jumping onto the house.
• Manage firewood and clutter: Store firewood away from the house and off the ground, and clear brush and debris from along the foundation.
• Store food securely: Keep pantry goods, pet food, birdseed, and animal feed in thick plastic, metal, or glass containers with tight-fitting lids.
• Move bird feeders: Keep feeders well away from the house, since spilled seed draws both rodents and squirrels.

One word of caution: if rodents may already be inside, sealing every opening at once can trap them in the structure, where they may chew a new way out or die inside a wall void. When there are signs of activity, exclusion works best when it is coordinated with pest removal.

Pest Proofing for Businesses

Commercial properties face many of the same rodent pressures as homes, along with a few of their own. Restaurants, warehouses, offices, retail spaces, and multi-unit buildings often have more doors, more deliveries, and more places for rodents to hide. For businesses, pest-proofing considerations include:

• Loading docks and bay doors: Large overhead doors with damaged seals are a frequent entry point, especially when they stay open during deliveries.
• Dumpster and trash areas: Waste storage close to the building can draw rodents toward exterior walls and doors.
• Break rooms and kitchens: Food left in desks, lockers, and shared kitchens can sustain a rodent population indoors.
• Stored inventory: Pallets, cardboard, and rarely disturbed storage areas provide both nesting material and cover.
• Shared walls and ceilings: In strip centers and multi-tenant buildings, rodents can travel between units through drop ceilings and shared wall voids.

For food-service and food-storage businesses in particular, rodent activity can also complicate health inspections and erode customer confidence. A year-round Greenville, SC, pest control plan that includes exclusion can help business owners address these risks before they become costly disruptions.

When to Call a Professional

Basic DIY winter proofing can go a long way, but many rodent problems warrant professional help. This is especially true if the situation involves:

• Hard-to-reach entry points: Rooflines, gable vents, and soffits often require ladders, roofing knowledge, and specialized exclusion materials.
• Active infestations: When rodents are already inside, removal and exclusion need to be coordinated so that animals are not sealed into the structure.
• Squirrels in the attic: Gray and fox squirrels are generally classified as game animals, so state wildlife rules may govern how they can be trapped or relocated, and because most squirrels raise more than one litter a year, a careful check for young is part of responsible removal.
• Repeat problems: If rodents keep returning after trapping, there is almost certainly an entry point that has not been found.

If you are comparing pest control companies in Greenville, SC, it is worth asking how each one approaches exclusion and follow-up, since sealing entry points is what makes results last.

Rodent Exclusion and Winter Proofing From Precision Pest and Wildlife Removal

At Precision Pest and Wildlife Removal, we help homeowners and business owners across the Upstate keep mice, rats, squirrels, and other rodents where they belong: outside. Our Greenville, SC pest control services pair a thorough inspection with targeted rodent exclusion, sealing the gaps, vents, and rooflines that lead rodents indoors, along with removal when animals have already moved in. 

Our approach to pest control in Greenville, SC, is built around a simple idea: the most effective rodent control keeps rodents from getting inside in the first place. Whether you are hearing scratching in the attic or simply want to get ahead of the season, now is a good time to schedule an inspection. Give us a call or book a visit online, and let us help make your home or business a much harder place for rodents to spend the winter..

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Frequently Asked Questions

When is the best time to rodent-proof a home or business?

Late summer and early fall are ideal, before rodents begin looking for winter shelter. That said, winter proofing is worthwhile at any point in the season, since rodents stay active through the colder months and will keep probing for a way inside.

Is spray foam enough to seal out rodents?

Spray foam can help fill small gaps, but rodents are capable of chewing through soft materials. In areas with heavy rodent activity, pairing foam or caulk with steel wool, hardware cloth, or metal flashing usually provides a more durable barrier.

Will traps alone get rid of rodents?

Not usually. Traps can reduce the number of rodents already inside, but they do not close the openings that let them in. Without exclusion, new rodents are likely to find the same entry points.

Do mice and rats hibernate in winter?

They do not. Mice and rats stay active year-round, which is one reason they look for warm, sheltered spaces inside homes and businesses once temperatures drop.

Are squirrels considered rodents?

Yes, squirrels, chipmunks, mice, and rats all belong to the order Rodentia, the largest group of mammals.⁴ Their constantly growing front teeth are the reason all of them gnaw, and the reason they can do so much damage once inside a building.

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References

1. Michael Sellner and Jordan Wicht, “How Many American Homes Have Pests?” United States Census Bureau, April 2021, https://www.census.gov/library/stories/2021/04/how-many-american-homes-have-pests.html. 
2. “Rodent-borne Diseases,” National Park Service, retrieved on November 10, 2026, from: https://www.nps.gov/articles/000/rodent-borne-diseases.htm. 
3. “How to Seal Up to Prevent Rodents,” Centers for Disease Control and Prevention, April 2024, https://www.cdc.gov/healthy-pets/rodent-control/seal-up.html. 
4. “Introduction to the Rodentia,” Museum of Paleontology, University of California, retrieved on November 10, 2026, from: https://ucmp.berkeley.edu/mammal/rodentia/rodentia.html.