Mice in the Walls: Recognize Sounds and Get Rid of Mice

Scratching, scurrying, gnawing — mice in the walls make themselves known especially at night through characteristic sounds. For residents, this situation is particularly unpleasant, as the mice are in an area that is difficult to access. However, simply ignoring the problem is not an option: mice in hollow cavity walls can gnaw on cables (fire hazard!), destroy insulation, and multiply rapidly. In this guide, you'll learn how to safely identify mice in walls, how the animals get there, and which methods work best to get rid of them.

Interpreting sounds in the wall correctly

Not every sound in the wall means a mouse infestation. Here's a comparison to help you correctly identify the cause:

Mice in the wall sound like this:

• Soft, quick scurrying: Small, nimble footsteps, often in short sequences. Mice move in jerky motions and pause in between.
• Scratching and scraping: Mice scratch at wood, plaster, and insulation. The sound is fine and scratchy.
• Gnawing: A rhythmic, grinding sound. Mice gnaw on wood, cables, and insulation material to wear down their teeth and obtain nesting material.
• Squeaking: Occasionally quiet, high-pitched squeaks can be heard — communication between mice.
• Timing: Mainly at night and in the early morning hours.

Distinguishing from other causes:

• Rats: Noticeably louder than mice, deeper scratching and heavier footsteps. Read more in our guide on rats in the basement.
• Martens: Even louder than rats, with distinct clattering and rumbling. Typical of martens in the attic.
• Birds: Fluttering and pecking, mainly during the day. Birds can get into cavities under the roof.
• Pipes and heating: Cracking and knocking from thermal expansion. Rhythmic and regular, independent of time of day.
• Insects: Woodworms and carpenter bees cause fine, regular ticking or boring sounds.

How do mice get into walls?

Mice in walls use various access routes to reach the cavities:

• Pipe penetrations: Unsealed penetrations for water, gas, and heating pipes provide easy access.
• Cable penetrations: Even small holes for electrical and network cables are sufficient.
• Cracks in masonry: Especially in older buildings, there are often cracks in foundations and masonry.
• Roof area: Mice climb up facades and enter wall cavities via the roof area.
• Basement: Via the basement and from there through cavities to the upper floors.

Once a mouse is in the wall, it can move through the entire cavity system of the building — from floor to floor and room to room.

Getting rid of mice in walls: Effective strategies

Ultrasound deterrence

Since mice in walls are difficult to reach directly, ultrasound is a particularly suitable method. The sound waves partially penetrate lightweight partition walls, making it unbearable for mice to stay in the cavities.

Strategically place traps

Since you can't directly catch the mice in the wall, place traps where the mice exit the wall — because they do this regularly to search for food. Typical exit points include:

• Behind the stove and refrigerator
• Under the sink (pipe penetrations)
• On heating pipes
• Near outlets and cable penetrations

Seal access points

Identify and seal all access routes with steel wool, cement mortar, or metal plates. This is the most important long-term measure. Important: Only seal the access routes when you're sure there are no more mice in the wall — trapped mice can die in the wall and cause unpleasant odors.

When to call a professional? Professional help for mice in walls

You should consult a professional pest control service in the following cases:

• If you can't find the access route
• If the sounds persist despite your own efforts
• If you suspect a larger infestation (sounds in multiple rooms)
• If you notice a burning smell (possible cable damage from gnawing)
• In older buildings with complex cavity systems

A professional can determine the exact position and extent of the infestation using special equipment (camera inspection, thermography) and initiate targeted measures.

Preventing mice in walls

To prevent the problem from recurring, you should plan ahead long-term:

• Permanently seal all pipe penetrations, cable penetrations, and cracks in masonry.
• Ensure seamless sealing during renovations and new construction.
• Operate the Professional Ultrasound Deterrent permanently in at-risk rooms.
• Store food consistently in sealed containers.
• Regularly check for signs of new infestations (droppings, gnaw marks, sounds).

Also read our main article on mice in the house for more tips on prevention and control.

Frequently asked questions (FAQ)

Can mice gnaw through walls?

Mice can gnaw through many materials, including wood, drywall, styrofoam, and thin plastic. However, they cannot gnaw through solid masonry, concrete, steel, and glass. In houses with drywall (gypsum board), mice can create new access points by gnawing holes in the panels. This is why using steel wool or metal mesh to seal access routes is so important — mice cannot bite through these materials.

Do mice in walls go away on their own?

No, mice only leave a shelter if they are actively driven out or living conditions deteriorate drastically (no access to food and water). Without countermeasures, mice in walls multiply and the infestation gets worse. A female can give birth every three weeks and produces 4 to 8 young per litter. Therefore, take action at the first signs.

Is it dangerous if mice in walls gnaw on cables?

Yes, this is a real danger. Mice regularly gnaw on electrical cables because gnawing helps them wear down their constantly growing front teeth. Damaged cable insulation can cause short circuits and, in the worst case, smoldering fires. If you have mice in your walls, have an electrician check the wiring once the infestation is eliminated.

How long can a mouse survive in a wall?

Mice can survive in wall cavities for several months to two years, provided they have access to food and water. They regularly leave the wall (usually at night) to search for food and then return to their protected shelter. Without access to water, mice can only survive a few days; without food, 2 to 4 days.