You know you have mice in your walls from telltale signs like noises (scratching, scurrying at night), finding their droppings (small, dark pellets), noticing a distinct musky odor, seeing grease marks, finding chewed materials, or discovering small holes/tunnels. These signs often appear in ceilings, behind baseboards, and near appliances, indicating they're nesting and traveling within your home's structure.
Signs of mice in the walls include droppings, nests, disturbed insulation, chewed or gnawed wood, scurrying and squeaking sounds, and a decaying odor. Mice can squeeze through openings the size of a dime.
Sound #1: Light Scratching and Gnawing
The most common early indicator of mice in walls is light, intermittent scratching or gnawing sounds. You'll typically hear these during nighttime hours when mice are most active.
Mice can live without water for months and without food for 1-2 weeks, but with access to both, they can live up to two years. And due to their constant reproduction, they can live in your walls indefinitely if measures aren't taken to remove them.
Set Traps and Baits
Or, try pre-mixed, ready-to-use Tomcat® Attractant Gel. Just a dollop of this gel on a mechanical trap attracts curious mice with no mess or fuss for you. Baits are a popular solution for controlling mice living in walls.
You may never see a mouse or rat unless an infestation is severe. Look for signs of rat or mouse infestation: Rodent droppings around food packages, in drawers or cupboards, and under the sink. Nesting material such as shredded paper, fabric, or dried plant matter.
I hear scratching inside my wall: what do I do?
In the spring and summer when temperatures are warm, mice are very active and will breed and expand their population outdoors. Mice have low cold tolerances, so when temperatures get colder in the fall and early winter months, they'll look for warmer shelter and reliable food sources to survive.
Learn about mice and their top predators in the wild and in urban environments.
The sounds you hear are often signs of mice foraging, nesting, or expanding their territory within your home's structure. Understanding why mice scratching walls in January is so common helps you take the right preventive steps, sealing entry points, removing attractants, and scheduling professional inspections.
Mice and rats commonly seek refuge in the cozy spaces in walls of your home. This is the most common place you will hear their quick light tapping and scratching sounds. FYI - walls act as a hidden highway system for them to move unseen through out a home.
Sometimes a dead mouse smell will last about a week, but it could continue for two or three weeks, depending on where the rodent's body died. It's important to remember that mice can carry some nasty diseases and germs with them, whether they're dead or alive.
TL;DR: If you hear scratching in the walls or spot mouse droppings, don't wait. Mice multiply quickly, chew through insulation and wiring (posing fire risks), and carry dangerous diseases. Ignoring the problem can lead to major property damage and health hazards. Prevention and fast action are key.
One of the more unpleasant but helpful mouse infestation signs is the strong ammonia-like odor caused by mouse urine and droppings. This smell is often most noticeable in enclosed spaces such as cupboards, crawlspaces, or behind appliances.
Professionals have training in the different rat species and which baits and traps work best for each. They know where to set traps for efficiency and can handle small and large infestations. They also offer a thorough inspection to discover all possible entry points and know how to seal them permanently.
Peppermint oil: Mice dislike the strong scent of peppermint. Soak cotton balls with peppermint oil and place them around entry points or nesting areas. Cayenne pepper or garlic spray: Mix cayenne pepper or garlic with water and spray it along fences, garden borders, and sheds to repel mice.
Mice are generally wary of humans and prefer to avoid direct contact. However, they may explore the sleeping area if they perceive a food source nearby. To prevent this, ensure your bedroom is free of food remnants, and take steps to seal entry points. If needed, consider using traps as a proactive measure.
During the winter food is more scarce, so when Spring arrives their natural food sources outside of your home are more abundant. Rest assured that between March through May rodents will begin making their way back outdoors.
Common Signs of Animals in Your Walls
In the early stages of a mouse infestation, you might notice other clues before spotting mouse droppings, like scratching sounds or musty odors. It's quite possible to see signs of mice, but no droppings if they've only recently infested your property or nest in hidden areas.
An infestation is often more extensive than it seems—mice are secretive dwellers, taking residence in wall voids to avoid detection while they nest and multiply. The duration of their stay can span from mere days to several months, depending on the accessibility of food sources and the level of safety they perceive.
The Top 5 Telltale Signs of Mice Activity
Some effective non-chemical mouse control procedures your exterminator will recommend include: Exclusion and sealing off sites that allow mice to enter a structure. Your rodent exterminator will seal openings greater than ¼-inch using screen, flashing, door sweeps, heavy-duty sealants, and other exclusion materials.
When you hear scratching, it's usually mice busily navigating the hidden parts of your house, searching for nesting materials or food. These sounds are most often heard during the quiet of the night, when mice are most active and when your house is at its quietest.