Yes, a squirrel can chew through drywall, wood, and even some metal. If your walls are made of anything softer than solid brick or steel, a determined squirrel can get through them.
The trouble is, they don’t chew for fun. They chew because they have to. A squirrel’s front teeth never stop growing, so gnawing is how they keep them filed down to a usable length. Your wall, your soffit, your siding, that’s just a convenient grindstone with a warm, dry nesting spot behind it.
Why squirrels chew through walls
This isn’t a bad habit I can train out of them. It’s biology. Their incisors grow continuously, and if a squirrel doesn’t gnaw on hard stuff, its teeth get too long to use.
The other half is motivation. Your attic and wall voids are warm, dry, and safe from predators. A squirrel that’s looking for a nesting site will test every gap and weak spot on your exterior until one gives. Once it finds a way in, it’ll keep enlarging the hole.
The two squirrels you’re most likely dealing with are the eastern gray squirrel and the fox squirrel. Both chew through the same materials, and both are relentless about it.
What they can and can’t chew through
| Material | Can a squirrel chew it? | Your best defense |
|---|---|---|
| Drywall | Yes, easily | Hardware cloth behind the drywall |
| Wood (pine, cedar) | Yes, easily | Metal flashing over the vulnerable spots |
| Aluminum siding | Yes, with effort | Replace with steel or cover with hardware cloth |
| Solid brick | No | Check the mortar joints instead |
| Deteriorated mortar | Yes, easily | Repoint the joints |
| Galvanized steel | No | Use it for all your exclusion work |
| Quarter-inch hardware cloth | No | The standard for keeping squirrels out |
The short version: use steel and quarter-inch hardware cloth. Skip chicken wire and anything thin enough to bend. A squirrel will get through both.
How to spot squirrel damage early
The earlier you catch it, the cheaper the fix. Here’s what to look and listen for:
- Scratching or scurrying inside walls, mostly around dawn and dusk.
- Chew holes the size of a quarter or bigger along rooflines, eaves, or siding corners.
- Drywall dust or debris piled below an entry point.
- Droppings in the attic. Squirrel droppings are oblong, about the size of a grain of rice.
- Nesting material like leaves, paper, or torn insulation near wall voids.
- A stale smell from urine, or worse, from a dead squirrel trapped inside.
tap along the wall with a screwdriver handle. A hollow or different sound tells you where a squirrel has tunneled behind the drywall.
What about brick and concrete?
Solid brick is the one thing a squirrel genuinely can’t chew through. Their teeth aren’t hard enough for fired clay. But the mortar between the bricks is a different story, especially old or crumbly mortar. A squirrel can claw and chew that loose enough to open a gap, then widen it.
Same with concrete. Fully cured concrete is too hard, but a crack from settling or frost is an open invitation. If you’ve got cracks wider than a quarter, seal them before a squirrel turns them into a doorway.
How to stop squirrels from chewing through
Prevention beats repair every time. Here’s what actually works:
- Seal gaps with quarter-inch hardware cloth. Cover anything bigger than a quarter. Screw it down tight. Don’t use chicken wire or metal lath, squirrels chew or bend both.
- Add metal flashing at the weak points. Flashing at a steep angle along rooflines, eaves, and the top of foundation walls stops them from getting a grip or gnawing through.
- Keep tree branches off the roof. Squirrels launch from branches onto your roof. Leave a good several feet of clearance between limbs and the roofline, and put a metal baffle around trunks that come close.
- Try a taste repellent. Hot-pepper sprays make surfaces unpleasant to chew without hurting the animal, but you have to reapply after rain. Skip mothballs and ammonia, they don’t work outdoors and they’re toxic to pets and kids.
- Use a one-way door for an active squirrel. It lets the animal out but not back in. Leave it up for a week or more, then seal the hole for good. Never seal a squirrel inside the wall, it’ll die there and you’ll smell it.
Repairing the damage
If a squirrel already chewed its way in, fix it in this order:
- Make sure the squirrel is gone first. Confirm no fresh droppings or daytime noise, and use a one-way door if you’re not sure. Never seal an animal in.
- Suit up. Droppings and nesting material can carry bacteria and parasites. Wear a respirator, gloves, and eye protection before you touch anything.
- Remove the damaged insulation. Mist it lightly so dust doesn’t go airborne, vacuum with a HEPA filter, and bag everything.
- Sanitize and seal the inside. Disinfect the cavity, then seal the interior hole with hardware cloth and patch the drywall.
- Seal the outside too. Cover the same entry point with hardware cloth or flashing, backfill gaps with low-expansion foam, and check it weekly for a month for signs the squirrel is trying to get back in.
When to call a pro
Some jobs aren’t worth the risk. Call a licensed wildlife removal pro if:
- You suspect chewed electrical wiring. That’s a fire hazard, and you need an electrician to look at it.
- The infestation is big or keeps coming back.
- The damage reaches load-bearing beams or joists.
- You can’t safely reach the entry point.
- Your local rules require a licensed operator to handle squirrel removal.
Frequently Asked Questions
Smaller than you’d think. A squirrel can squeeze through a hole barely bigger than an inch and a half. If you can fit a golf ball through it, a squirrel can fit its body and skull through. That’s why the rule is to seal anything wider than a quarter.
They’ll pull it apart or push through loose steel wool, especially once it rusts. Use quarter-inch galvanized hardware cloth instead. Steel wool works as a temporary filler, but only with a rigid barrier behind it.
Don’t count on it. If it’s nesting or it’s breeding season, it’ll stay, and it’ll keep gnawing to expand the space. You usually need a one-way door or professional removal.
No, cured concrete is too hard. But they’ll exploit cracks from settling or frost. Seal cracks wider than a quarter with hydraulic cement before they get bigger.
Inspect the roofline, soffits, eaves, and the seam where siding meets the foundation, and look for chew marks and droppings. Tapping the walls for hollow spots tells you where they’ve been tunneling once they’re inside.
