Does Insulation Help Keep Pests Out?

When most homeowners think about insulation, they picture warm, cozy rooms in the winter and a cool retreat from summer heat. But did you know insulation can also play a vital role in keeping pests out of your home? That’s right—insulation isn’t just about energy efficiency and comfort. It can also serve as a line of defense against unwanted guests like rodents, insects, and other critters.

At Koala Insulation of Greater Knoxville, we’re proud to provide insulation solutions that not only improve your home’s thermal performance but also help deter pests from entering and nesting where they don’t belong. In this blog, we’ll explain how insulation works to discourage pests, which types are most effective, and where you should focus your efforts.

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Why Are Pests Attracted to Certain Homes?

Pests are always looking for food, water, and shelter—and your home can provide all three, especially in vulnerable areas like attics, crawl spaces, basements, and walls. Gaps, cracks, and unsealed areas allow easy access for:

• Mice and rats
• Squirrels
• Roaches and ants
• Spiders
• Silverfish
• Termites

Once inside, they can cause serious damage—chewing wires, contaminating insulation, nesting in walls, and even compromising your home’s structure.

That’s why insulation and air sealing are critical components in an integrated pest management strategy. At Koala Insulation of Greater Knoxville, we offer insulation solutions that don’t just block heat loss—they help block pests too.

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How Insulation Helps Deter Pests

Insulation helps keep pests out in a few important ways:

1. Sealing Entry Points

Many types of insulation—especially spray foam—expand to fill cracks, holes, and gaps in your home’s building envelope. These are the same tiny entryways that rodents and bugs use to sneak inside. By sealing them off, insulation acts as a physical barrier.

At Koala Insulation of Greater Knoxville, we often combine insulation installation with air sealing to close up pest-prone areas like:

• Rim joists
• Attic corners
• Crawl space vents
• Gaps around pipes and wiring
• HVAC duct penetrations

2. Making Spaces Less Habitable

Pests love environments that are warm, moist, and undisturbed. Poorly insulated crawl spaces and attics often check all three boxes. When insulation is installed correctly, it reduces humidity, stabilizes temperature, and eliminates the kind of dark, damp conditions pests seek out.

Additionally, dense insulation like closed-cell spray foam is not easy for pests to chew or nest in, unlike older fiberglass batts or loose fill insulation, which mice and insects tend to tear apart for nesting material.

3. Discouraging Re-Entry

Once your home is properly sealed and insulated, it becomes much less attractive to pests. Even if they find a way onto your property, they’re less likely to find an easy way inside. This makes insulation a great long-term investment in pest prevention.

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Best Types of Insulation for Pest Control

While most insulation provides some barrier against pests, certain materials are more effective than others:

Spray Foam Insulation

Spray foam is one of the most pest-resistant insulation types available. It expands on contact, sealing off cracks and crevices where pests could enter. Its dense structure also makes it hard for rodents to chew through or nest in.

At Koala Insulation of Greater Knoxville, we frequently recommend spray foam for crawl spaces, attics, and rim joists—areas that are high-risk for pest activity.

Cellulose Insulation (with Borate Treatment)

Cellulose insulation is treated with borates, a natural mineral that deters insects like cockroaches, ants, and termites. While it doesn’t create a physical seal like spray foam, it can still be an effective part of a pest-resistant insulation plan, especially when used in combination with air sealing.

Fiberglass Insulation

Fiberglass doesn’t attract pests, but it can be compromised if pests are already present. Mice and rats have been known to tunnel through fiberglass and use it for nesting material. However, if your home is properly sealed and pests are prevented from entering in the first place, fiberglass can still be a viable choice.

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Where to Focus Insulation for Pest Prevention

At Koala Insulation of Greater Knoxville, we advise homeowners to focus their pest-prevention insulation efforts in these key areas:

Attics

Rodents and insects often enter through roof vents, eaves, or poorly sealed soffits. Insulating and air sealing your attic is a powerful way to stop them from spreading into the rest of your home.

Crawl Spaces

Crawl spaces are a hotspot for pests, especially in Tennessee’s humid climate. We offer crawl space insulation and encapsulation to block moisture and eliminate pest entry points.

Rim Joists

The narrow gap where your foundation meets your framing is a favorite entry point for rodents. We use spray foam insulation in these spots to seal and insulate simultaneously.

Basements

Basements can attract pests due to their cool, damp conditions. Insulating basement walls and sealing gaps around pipes and windows helps keep pests out and moisture under control.

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Insulation Alone Isn’t a Pest Control Cure

While insulation can be an excellent deterrent, it’s not a replacement for proper pest control. If you already have an infestation, you’ll need to work with a licensed exterminator first. Once the pests are removed, Koala Insulation of Greater Knoxville can help ensure they don’t return.

We work with homeowners to provide a comprehensive insulation and air sealing strategy that not only boosts energy efficiency but also strengthens your home’s defenses against pests.

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Signs You May Have Pests in Your Insulation

Not sure if you already have unwanted visitors? Keep an eye out for these common warning signs:

• Droppings or chewed insulation
• Scratching noises in walls or ceilings
• Nesting material in attic or crawl space
• Foul or musty odors
• Gaps or cracks near entry points

If you suspect pest activity, call us for an evaluation. We can recommend next steps and help restore your home’s insulation afterward.

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Call Koala Insulation of Greater Knoxville Today

Insulation doesn’t just save you money on energy bills—it also helps protect your home from pests. Whether you’re building new, upgrading old insulation, or sealing off drafty areas, we can help.

Call Koala Insulation of Greater Knoxville at (865) 417-9005 or visit https://koalainsulation.com/greater-knoxville to schedule your free estimate. Let’s create a more comfortable, energy-efficient, and pest-resistant home—together!