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MiceMice in the Walls: Signs, Causes and Fixes
Light scratching or skittering inside a wall at night usually means mice are using the wall as a hallway. Trap where they come out, seal where they get in, and avoid poison that leaves dead mice inside.
Updated November 4, 2026
If you hear light, quick scratching inside a wall at night, especially near the kitchen, a bathroom or an outside wall, mice are the most likely cause. They rarely live in the middle of a wall. They use wall cavities as protected hallways between their nests and food, entering from the crawl space, basement or attic and leaving through gaps under sinks, behind appliances and at baseboards.
The fix is to trap them where they come out and seal the places they get in, not to cut into the wall. Here is how to confirm it, find the route and fix it.
Signs you have mice in the walls
- Scratching, skittering or light gnawing sounds after dark, often near the floor or ceiling.
- Droppings under the kitchen sink, behind the stove or refrigerator, or in lower cabinets on the same wall.
- Small holes or gnaw marks at baseboards or where pipes enter the wall.
- Grease marks along the bottom of the wall near openings.
- A musty odor near outlets or registers on that wall.
- Pets staring at or pawing at one spot on the wall.
Mice are mostly active at night, which is why the noise seems to start once the house quiets down.
Mice or something else?
Heavier, slower movement and louder gnawing point to rats. Noise during the day, especially early morning and late afternoon, often means squirrels in the attic or upper walls. Ticking and popping that follows the heat or water heater cycling is usually pipes or ducts expanding. Our noises article goes through the differences. Droppings settle it: check the cabinets and the crawl space or attic next to the noisy wall.
Want a provider to look at it?
Describe what you are seeing and where. The call is free and goes to an independent rodent control provider who serves Richmond and the nearby counties.
How mice get into wall voids
Most interior walls sit on a wooden bottom plate, with pipes and wires passing through holes drilled in it. Those holes are usually larger than the pipe or cable. From the crawl space or basement, mice climb up through the gaps into the wall cavity. In the attic, the same gaps at the top plate let them in from above.
Older Richmond homes make this easier. Many houses in the Fan, Church Hill, the Museum District and Northside have plaster walls and framing where cavities run between floors, so a mouse can climb from the crawl space to the second floor without entering a room. Old radiator and gas pipe holes, chimney chases and gaps behind built-in cabinets add routes. Row houses and duplexes share walls, so mice may come from next door.
How to get mice out of the walls
- Find the exits. Check under the kitchen and bathroom sinks, behind the stove, dishwasher and refrigerator, inside lower cabinets and at baseboards on the noisy wall.
- Set snap traps at the exits. The CDC recommends placing traps against the wall where you see signs, with the bait end touching the wall. Cabinets under sinks are good spots once they are cleared out.
- Check below and above. Go into the crawl space or basement below the wall and look for droppings around pipes and ducts going up. Do the same in the attic above.
- Seal after catching. Once catches slow down, seal the gaps around pipes and wires with copper mesh or steel wool held in place with sealant, and use metal or mortar for larger openings. The CDC lists steel wool with caulk or spray foam for small holes and metal, cement or hardware cloth for larger ones.
- Seal the outside too. The mice got into the house somewhere first: crawl space vents, garage door corners, utility entries or gaps at the foundation.
Why not poison or cutting the wall?
Poison bait often leads to mice dying inside the wall, and a dead mouse in a wall cavity can smell for weeks, especially in Richmond's summer heat. Trapping at the exits lets you remove them. Cutting holes in drywall or plaster is rarely needed and is usually saved for reaching a dead mouse once the smell shows where it is. Our dead rodent smell article covers that.
Avoid sealing the exits while mice are still inside the wall. They will either die there or chew a new exit.
When to get help
If you have mice in several walls, hear them on more than one floor, or have been trapping for weeks without the noise stopping, the entry points are likely somewhere you have not found or cannot reach. A provider can trace the route through the crawl space and attic and seal it. See mice in walls removal for what that job includes. Renters should tell their landlord in writing; Virginia law requires tenants to promptly notify the landlord of pests.
Call a local rodent provider
The call is free. Describe the problem, ask what the visit includes, and get a written price before any work starts.
Questions people ask
Will mice in the walls go away on their own?
Rarely. They have food, shelter and a protected route. Without trapping and sealing, the population usually grows.
Can mice chew through drywall?
Yes, they can gnaw through drywall and many soft materials, which is why sealing uses metal, mesh or mortar.
Should I put poison in the wall?
It often causes mice to die inside the wall, leading to weeks of odor. Trap at the exits instead.
How long until the noise stops?
Often one to three weeks once traps are at the exits and gaps are sealed. The CDC's guide: no catches and no new signs for a week means they are gone.