How To Read Gnaw Marks
Look closely at the edges of the damage. The size and shape of the tooth marks point to the animal that made them.
| Mice | Rats | |
|---|---|---|
| Tooth marks | Tiny, fine grooves, close together | Larger, deeper grooves, often in pairs |
| Edges | Neat, small scraping | Rough, ragged, splintered |
| Holes | Small and clean, roughly dime-sized | Larger and torn, roughly quarter-sized or bigger |
| Where you find them | Kitchens, pantries, cabinets, walls | Basements, garages, lower floors, outdoor bins |
Droppings found near the damage help confirm what you're dealing with. Our guide to mouse droppings vs rat droppings shows how to tell them apart.
If you've found chewed corners on a baseboard, shredded cereal boxes or a ragged hole behind the stove in your Hawthorne home, you're looking at a reliable sign of rodents. Gnaw marks tell you a lot: which animal made them, how recently it was active and where it's been traveling. Below, we'll cover why rodents gnaw, how to read the marks they leave, what they damage and what to do about it. If you're seeing fresh chewing, our rodent control services can help you find the source.
Why Rodents Gnaw On Everything
Mice, rats and squirrels are rodents, and all rodents share one trait. Their front teeth, called incisors, keep growing throughout their lives. Gnawing wears those teeth down and keeps them sharp. That means a rodent chews even when it isn't hungry.
Rodents also gnaw to get where they want to go. They'll widen a small gap in a door, a vent screen or a wall to squeeze through, and they'll chew into boxes, bags and bins to reach food or nesting material. So gnaw marks often show up along travel routes, near entry points and around food storage.
Old Damage Or New Activity?
Gnaw marks you find in an older house might be years old. A few clues tell you whether rodents are active now:
- Color. Fresh gnawing on wood looks light and bright, like freshly cut wood. Old marks darken and look weathered.
- Edges. New marks have sharp, crisp edges. Old ones look worn and smooth.
- Debris. Small wood shavings, paper scraps or plastic bits under the damage point to recent chewing.
- Change over time. Take a photo of the spot and check it again in a few days. If it's bigger, rodents are still at work.
What Rodents Chew In Your Home
Gnaw marks aren't just cosmetic. Rodents chew a wide range of materials, and some of the damage is serious:
- Food packaging. Cardboard, paper and thin plastic bags in pantries and garages.
- Wood. Baseboards, door corners, cabinet edges and window trim.
- Wiring. Electrical wire insulation in walls, attics and appliances, which can create a fire hazard.
- Pipes and tubing. Plastic water lines, drain lines and ice-maker tubing.
- Insulation and stored items. Fiberglass, foam, cardboard boxes, fabric and paper used for nesting.
Gnawing near the floor along a wall, around pipes under the sink or at the corner of a door often marks the spot where rodents enter a room. Those spots are worth noting before you call for help.
Don't Forget The Outside
Some of the most useful gnaw marks are on the outside of your home. Walk the perimeter and look at the bottom corners of garage doors, the edges of wooden steps, vent covers, crawl space doors and the trim where siding meets the foundation. Check plastic trash and recycling bins, sheds and the lids of compost bins as well. Chewing at ground level outside often means rodents are testing the house for a way in. Catching it there, before they reach the walls and kitchen, is the easiest time to fix the problem. If you find chewed spots on both the outside and inside of the same wall, you've likely found an active entry point.
What To Do About Gnaw Marks
- Check for live activity. Look for fresh droppings, new chewing and grease marks along walls.
- Protect food. Move dry goods and pet food into hard plastic, glass or metal containers.
- Inspect wires carefully. If you see chewed wiring, have an electrician check it before using that circuit.
- Clean up safely. Wear gloves and wet down droppings with a disinfectant before wiping them up rather than sweeping or vacuuming them dry.
- Find the openings. Look for gaps around pipes, vents, doors and the foundation near the damage.
- Use materials rodents can't chew. Foam, rubber and thin plastic don't stop a determined rodent. Metal and other hard materials hold up much better.
When To Call A Professional
If you're finding fresh gnaw marks in more than one room, damage to wiring or pipes, or chewing that keeps coming back after you've set traps, it's time for an inspection. Our NJ DEP-licensed technicians trace the gnawing back to the entry points, identify whether you have mice or rats and recommend a plan to remove them and seal those entry points with pest-resistant materials. We use Integrated Pest Management and EPA-registered, eco-safe products, and our work is backed by the EcoGuard Guarantee.
Gnaw marks are a rodent's calling card. Reading them correctly helps you act early and keep your Hawthorne home protected from further damage.