Rat and mouse article

Mice in the Walls: How to Find Them and Get Them Out

Updated November 4, 2026

You can't trap a mouse inside a closed wall. Find the openings it uses, under sinks, behind appliances and around pipes, trap there, and seal once the catches stop.

Light scratching inside a wall at night, usually near the kitchen or a bathroom, most often means mice. They use the hollow space inside walls as a hallway between food and a nest. You can't reach them in there, so the work happens at the openings: under sinks, behind the dishwasher and fridge, around pipes and outlets.

Here's how to confirm it, find the openings and get them out without leaving one to die inside the wall.

Is it mice?

Mice make a light, quick scratching or scurrying sound, often low in the wall or under cabinets, mostly after dark. Rats are heavier, and in Miami they're usually up in the attic or ceiling, where the sound is more like running or thumping. Look for rice-size droppings in kitchen drawers, under the sink and behind appliances. Rats vs. mice covers the differences.

How they get into the wall

UF/IFAS says a mouse can get through a 1/4-inch gap. Common openings into a wall cavity in a Miami home:

• Where plumbing goes into the wall under the kitchen and bathroom sinks
• Behind the dishwasher, fridge and washer, where water and drain lines pass through
• Gaps behind cabinet kick plates
• Around electrical boxes and outlets
• At the garage wall, around the water heater and laundry lines
• In condos, the plumbing and wiring chases that connect units

Find the doors

Empty the cabinet under the kitchen sink and look at the pipe holes with a flashlight. A ragged gap, droppings on the cabinet floor or chewed packaging tells you that's a doorway. Do the same under bathroom sinks and behind the washer. Pull the kick plate under the kitchen cabinets if it comes off easily. Note where you hear the sound for a few nights. That narrows the search to one wall or one corner of the house.

Trap at the openings

Set snap traps at the openings you found and along nearby walls, with the trigger end against the wall. A small dab of peanut butter works. UF/IFAS ENY-224 notes mice usually approach a trap the first night, so a trap that catches nothing in a few nights should move. Use several traps. Keep food in hard containers so the traps are the easiest meal around.

Avoid poison in walls. A mouse that eats bait can die inside the cavity, and in a Miami summer the smell builds quickly. If that happens, see dead rodent smell.

Seal after the catches stop

Don't seal an opening while mice are using it, or they'll be stuck inside the wall. Once a few nights pass without catches or fresh droppings, close the gaps. Pack copper or stainless mesh into pipe holes and cover with sealant. Hardware cloth with openings no larger than 1/4 inch works over larger gaps, per UF/IFAS ENY-224. Plain steel wool rusts fast in Miami humidity. See gap sizes and sealing materials.

Concrete block walls

Many Miami houses are concrete block on the outside, with furring strips and drywall inside. That leaves a narrow space between block and drywall where mice can run. The way in is usually where something passes through the block, like a pipe, a hose bib, a dryer vent or the AC line, or at the base of a wall where the drywall meets the slab. Check those spots on the outside of the wall where you hear the noise.

In a condo

If you're in a tower, the mice in your wall may have come up a chase from the trash room or the garage. Seal your side, set traps, and tell management in writing. Ask whether neighbors on your stack report the same thing. If they do, the building has to deal with its shared spaces. See condo and apartment rodent control.

When to call a provider

Call if the scratching continues after a week of trapping, if you can't find the openings, if you smell something dead, or if lights flicker near the wall. A technician can find openings you can't see and decide whether a small access hole is needed. Mice in walls removal covers the visit.

Why the kitchen wall

Mice stay close to food. In most Miami homes, that puts them in the walls around the kitchen and pantry, where pipes for the sink, dishwasher and fridge pass through and crumbs collect under appliances. Pull the stove and fridge out once and vacuum behind them, then keep the area clean. A kitchen with no crumbs behind the appliances gives the traps less competition.

Clean up after

Once the catches stop, clean the cabinets and floors where you found droppings. The CDC's method: gloves on, spray droppings with disinfectant or a bleach solution, let it soak about five minutes, wipe up with paper towels and bag them. Don't sweep or vacuum dry droppings. Throw away any food in a chewed bag or box. Check the same spots again a few days later. New droppings mean a mouse is still getting in.

Related services: Mice in Walls Removal, Mouse Control, Rodent Exclusion