Mouse noises and other signs of mice infestation

The mouse is drinking coffee

Having a mouse problem in your home is quite common in London though it is a huge inconvenience. Mice can cause damage to your property and be very distressing, especially to those with a fear of mice. To minimise the damage and distress they cause, it’s important to recognise that you have mice early. The sooner you detect a mice problem, the quicker you can call a pest control expert to resolve it. The signs of mice can vary greatly from very faint mouse noises to very strong smear marks. We will go over them in more detail and associate them with the most likely context. Here are the signs of mice you should be looking for in your home. 

Mouse noises

The first signs of mice that many people notice are mouse noises within walls or under the floorboards. They scratch and claw away at wooden surfaces and plasterboards, which makes a distinctive rustling sound. It may not be loud enough to hear if you’re watching TV or talking with friends. However, when your home is quiet, you’ll notice the rustling. It generally occurs where mice tend to spend their time since it’s dark, safe, and usually provides access to neighbours’ properties. Since mice are nocturnal creatures, you’re more likely to hear them at night. This is especially true if you have a bed with a ceiling sliding down or boxed-in pipework nearby.


Droppings dotted around your house are the most obvious signs of mice you may find. They may be scattered randomly, but will often be located near food sources. For instance, you might find them on kitchen surfaces, in cupboards, or even near skirting boards that mice use to access the inner walls. Droppings are approximately the size of a grain of rice (between 3 and 6mm in length). They are a deep, dark brown/black in colour. In some cases, mice can leave as many as 80 droppings in a single night, making their presence quite evident. You’ll quickly realise if you have a mice problem. The best places to find these signs of mice are under the kitchen sink unit or at the back of the washing machine.

Bite marks

Mice love to nibble and bite. Whether it’s food or harder surfaces, mice are almost constantly gnawing away at things. This is because their teeth grow continuously, so mice must grind them down regularly. Unfortunately, your cupboards, the base of the doors, and furniture provide excellent surfaces for this, making them prime targets for mice. These signs of mice activity can easily be dismissed as unimportant by the untrained eye. Follow the skirting boards and look for an area of the carpet that is missing in the shape of a half moon. Look to the back of your cupboards and around the corners, if you notice gnaw marks or debris. If you find anything, remove it or clean it away. Then check again after a few days, and then if you find more of it, you definitely have signs of mice activity. 

Footprints and tracks

In more dusty areas of your home, such as lofts, basements, or even unused cupboards, you may notice small footprints from mice. You may also notice tails marks in the dust where the tail has swiped along the surface. These are the kind of signs that would be left by a single mouse. But the most common signs of mice will be in the form of a smear mark or a run, created by many instances of mice traveling following the same route. A run is easy to understand, as you go through the same path, the fur clears the dust, debris, and webs aways to create a clean line surrounded by dust.

A smear mark is more tricky and is often mistaken for dirt or a spill. As mice go over an edge or cable time and time again, that sudden increase in pressure causes a slightly larger deposit of fat and dirt from the fur. After a long period, it shows as a dark section across what would otherwise be white. Smear marks will often be found on the electric power cable of fridges, of the kickboard of the kitchen units below the dishwasher, or in the corner units.

As professionals, we exploit such signs of mice activity using fluorescent tracking dust or gel. But if you notice such tracks and suspect that you have a mice problem, a way to test the theory is to lay some flour or talcum powder and check back each day to see if more tracks appear. If you have a mice infestation, it won’t be long until you see fresh tracks. 

Your pets reacting to mouse noises

If you have a pet, in most cases, they’ll hear mouse noises before you do. If you notice your pet acting strangely, such as being very excited and interested in a particular place in your home, such as a certain cupboard or a corner of a room, then it’s likely you have mice. Pets such as cats and dogs will hear the mouse noises and, most notably, smell them. Mice, especially when there are many, will give off an odour, and it may become so strong that you notice it too. Examine the area that your pet is focused on and check for things like droppings and gnaw marks. Where there are pets, there is also pet food. Check at the back of the fridge if you find any dog or cat biscuits that the mice would have dragged there.


Mice will make nests out of things like pieces of fabric, paper, and even plants. In all my years I only stumble upon a nest containing pups twice, under a chest of drawers in a bedroom, and another time within the clutter of a cupboard. Otherwise, I would assume that mice would rather build their nest where it is much safer and secluded within the walls or under the floorboards. The signs of mice activity you are actually looking for are carpet fibers that are loose for some unexplained reasons, or even on clothes.

Sometimes, we find that mice were using our bait boxes to create a nest within. We would only find a half-built nest since the mice normally do not leave long enough to use it. But the interesting bit is the variety of materials you find in it, paper, plastic, fabric, even stones. Look around in dark, remote areas of your home, such as behind kitchen appliances or in the corner of your loft or basement. Finding a nest is a guarantee that you have a mice problem and that you need to call a pest control expert immediately before the problem worsens. 

Mouse noises or any other signs

You may not experience all of these signs of mice, but seeing just one is reason enough to get in touch with us. Here at Inoculand, we have over a decade’s experience in taking care of people’s mice problems in and around London. We’re so confident in our mouse control and proofing service that we offer a one-year guarantee following after the proofing is done. Read more about our mouse control service here.