Repeated scratching in walls at night can indicate rats or mice, but sound alone cannot confirm the animal or the size of the problem. Record where and when it occurs, look for accessible evidence and seek inspection before cutting into a wall.
Rodents are one possible cause
Rats and mice are nocturnal. During the day they stay hidden; after dark, when the house is quiet, they move along their routes through wall voids, under floors and above ceilings, and they gnaw as they go. That is the scratching you hear.
Why the walls?
Wall cavities are a rodent's ideal highway: warm, dark, hidden, and connected to the whole house. Pipes and cable runs give them ready-made paths from room to room.
Why you shouldn't ignore it
Inside the walls, rodents chew electrical wiring, a real fire risk, shred insulation, and breed. A faint scratch this week can become a real infestation within a month or two. (See are rats in the walls dangerous.)
What to do
- Find the entry points: check where pipes and cables enter walls; seal gaps larger than 2 cm.
- Cut off food and water: the reasons they are travelling to begin with.
- Make the space unwelcoming: remove food and clutter, and consider a deterrent in the room as an extra layer.
What the sound tells you
Different noises point to different things. Listen for a night or two before acting:
| What you hear | Likely cause |
|---|---|
| Light, fast pitter-patter | Mice, or a small rat running along a route |
| Heavier scurrying and thumps | Rats, which are much bigger than mice |
| Steady gnawing or grinding | A rodent chewing wood, plastic or wiring |
| Squeaking, especially high-pitched | Young rodents, a sign of a nest nearby |
| Scratching only at dawn and dusk | Possibly birds or squirrels in the roof, not rodents |
Not sure whether it's rats or mice? See rats vs mice, how to tell the difference.
How to pinpoint where they are
- Note the time and place each night. The same spot at the same hour usually means a regular route or a nest.
- Follow the pipes and cables. Sound often travels along plumbing runs and wiring ducts, which is where rodents move.
- Look for evidence nearby: droppings, gnawed skirting, greasy rub marks or shredded paper close to where the sound is loudest.
- Check the outside wall at the same height for gaps, broken vents or holes where pipes enter.
Our guide on how to find a rat nest in your house goes step by step.
When to call a professional
- You hear activity in several rooms or on several floors.
- You smell burning plastic, or lights and sockets start misbehaving, possible chewed wiring. Have an electrician check it.
- You notice a strong, rotten smell, a rodent may have died inside the wall.
- The noises keep coming back after you've sealed the obvious gaps.
Why it can feel louder than it is
Wall cavities act like a drum: a small animal scratching on plaster or a ceiling board can sound much bigger than it is, especially in a silent house at 2 a.m. That doesn't make it harmless, but it does mean a single rat can sound like several. Evidence such as droppings tells you more about the size of the problem than volume does.
For why you hear scratching in the walls at night, the EchoRepel Home Rat Repellent is a supporting option using ultrasonic sound that rats and mice want to avoid. It is poison-free. For why you hear scratching in the walls at night, use the device only as instructed and assess new signs rather than assuming protection.
Keep a sound log without opening the wall
Note the room, approximate time, duration and whether heating, water use or an appliance was operating. Building materials and plumbing can also make noises, while a cavity can carry an animal's sound away from its actual position. A recording may help a professional compare the pattern.
Look at accessible skirting, pipe entries and nearby storage for droppings, gnawing or pulled-out material. Photograph signs in place. Do not drill where the sound seems loudest, because wiring or pipes may be directly behind the surface.
Electrical warning signs change the response
Burning smells, flickering lights, damaged sockets or visible cable chewing require an electrician's advice. Stop using affected equipment and, where safe, follow the electrician's instructions about isolating the circuit. Do not remove socket covers or probe a cavity yourself.
If there is smoke or an immediate fire concern, leave the area and contact emergency services. Pest identification can wait until the electrical hazard has been addressed. Repeated resetting of a tripped circuit is not a way to establish that the noise is harmless.
Agree how inspection and repair will fit together
A pest controller can assess routes while a building professional arranges safe access if opening is needed. Ask who will remove contaminated material, check wiring and close the opening afterwards. Include any shared shaft or adjacent property in the investigation where evidence points that way.
Removal and sealing should be coordinated to avoid trapping animals inside. After work, compare fresh physical evidence and the sound log rather than expecting a single quiet night to prove success. A room device should not be assumed to transmit effectively through a solid wall. Follow official clean-up guidance for droppings and seek medical advice for bites or illness after exposure. The aim is to identify the cause safely, rather than treating every nighttime sound as proof of an infestation.
Frequently asked questions
Should I drill a hole beside the loudest sound?
No. Hidden wiring and pipes make that unsafe, and sound may travel from elsewhere. Arrange an inspection and planned access if professionals decide an opening is needed.
What if the circuit breaker also trips?
Stop using affected equipment and seek qualified electrical advice. Repeatedly resetting protection does not establish safety, especially with a burning smell or suspected cable damage.
Does one quiet night mean the wall is clear?
No. Activity can vary. Compare the sound log with fresh evidence and the professional follow-up plan before assuming removal and entry repairs are complete.
Can tapping on the wall make the animal leave?
It may interrupt a noise temporarily without closing an entry or removing a nest. Avoid striking or drilling the wall, and arrange an inspection if the activity repeats.