In Mouse, News

A mouse invasion is a real problem that affects many homeowners. They often don’t realize that there are mice in their home until it’s too late. Noises, droppings, urine – there are plenty of warning signs.
Once a house is infested with mice, it often requires thorough extermination to solve the problem. That’s why it’s important to take preventive action as soon as these signs appear. So in this article, our Montreal exterminators explain how to tell if a mouse is in your home.

Signs of mice in the house

The warning signs of a mouse invasion are quite specific. Although malignant and small, mice in your home will let you know of their presence. Here are the signs your mouse exterminators will look for so you can inspect your home.
1. Mouse droppings
2. Mouse noises
3. Mouse sounds
4. Paw prints
5. Grease marks
6. Nibbling marks
7. Mouse nests
8. Odors

1. Mouse droppings

Mouse droppings are one of the most obvious signs of their presence in your home. Areas where you’re likely to find mouse droppings include closets, drawers, the fridge, dark nooks and crannies, basements and attics. In fact, you’ll find them near what mice eat and possibly along walls too, because these are the routes they take to get to their hiding places. Be attentive during your inspection and look for these characteristic clues to the presence of mice.

How can you tell if they’re mouse droppings?

Mouse droppings are small, generally cylindrical in shape and pointed at the ends. They look a little like grains of rice or pellets, black or brown in color, depending on the mouse’s diet.

Mouse droppings are generally a few millimeters long, making them significantly smaller than rat droppings.

2. Mouse noises

Noises are a very telling sign of infestation. Indeed, these rodents are not only visible, they also leave sound clues that can alert you to their presence in your home.

Listening carefully for specific noises associated with mice can be an effective way of detecting their activity and taking action quickly. What noises?

Scratching noises

Mice are nocturnal animals and you can often hear them scratching surfaces during the night. You can hear these scratching noises in walls, ceilings, attics, cellars and spaces under floors.

Mouse scratching noises can be light, but repetitive. They are often caused by nest-building or by mice in the walls moving around. Try listening carefully at night for these distinctive noises.

Crackling, cracking and crunching sounds

Mice can also make noise when they chew on hard materials like wood. Areas of the house where you might hear these cracking, crackling or crunching sounds include walls, baseboards, floors and wooden furniture.

Chewing sounds can vary in intensity and frequency, depending on what the mice are doing.

Can you hear mice running on floor?

Yes! Mice are agile animals and you can sometimes hear them taking small, quick, light steps. These footsteps are often audible at night when mice are most active. They can sound like small paws moving quickly over surfaces such as floors, walls or ceilings.

If you hear these noises regularly, especially during the nocturnal hours, it’s likely that there’s one or more mice in your home.

3. Mouse calls and other sounds

Mice have their own sound language to communicate with each other and express various emotions. Understanding these distinctive sounds can provide valuable information about mouse activity and behavior in your environment.

What does a mouse sound like?

They squeak. Mice can emit high-pitched, shrill squeaks in certain situations. These calls are generally used for communication between rodents or to express fear or stress. You may hear these mouse calls when there are social interactions between individuals, when they are confronted by predators or when they feel threatened.

Be on the lookout for high-pitched, rapid noises that may sound like screams and may indicate the presence of mice in your home.


These small rodents can also produce chirps that sound like rapid, high-pitched squeaks. These chirps can have several purposes, such as to mark territory or express dominance over other mice. Chirps may also be a way for a mouse to get attention or to express excitement.

Do mice hiss?

Mouse hissing is often associated with conflict or confrontation. When a mouse feels threatened or finds itself in the presence of a predator, it may hiss to signal aggression or to try to intimidate its opponent. Hissing can also be heard when mice are fighting or competing for resources.

4. Nibbling tracks

Mice need to gnaw constantly to wear down their growing teeth. They can nibble on a variety of materials in your home, such as electrical wires, cardboard, wood and even plastic pipes.

  • Look for nibbling marks along walls, on furniture, food packaging and plastic objects. Irregular edges and small teeth marks are key indicators of a mouse invasion.
  • If you notice gnawed electrical wires, perforated food packaging, holes in walls or wood, this may indicate the presence of mice actively nibbling to access food, move around or build nests.
  • Compare nibbling marks with mouse droppings and other signs of activity to get a more complete picture of the infestation. If you find both mouse droppings and nibble tracks in the same area, it’s likely that mice are active there.

5. Mouse paw prints

Mice often leave paw prints in dusty or dirty areas of your home. Their prints are small, usually 1 to 2 centimeters long, with five fingers and distinct claw marks.

To detect mouse paw prints, you can use flour or talcum powder. Sprinkle these substances in suspicious areas, such as along walls, under furniture or where you think mice enter. After a while, come back and examine the sprinkled areas for mouse paw prints. Fresh paw prints will be clear and distinct.

If you find mouse paw prints, this not only confirms the presence of mice in your home, but can also indicate the routes they take and the areas where they are most active. This can help you target your efforts to control the infestation!

6. Grease marks on walls

As mice move along walls, they rub their bodies against surfaces, leaving grease or dirt marks. These marks, known as “grease trails”, can be seen along routes frequented by mice, such as baseboards, windowsills and electrical wires.

Grease streaks often appear as dark lines along walls, usually at the height of a mouse’s head. In addition to grease streaks, you may also notice dark spots or accumulations of dirt in places where mice hide or build their nests.

7. Mouse nests

Mice build nests to reproduce and protect themselves. These nests are often located in dark, warm and isolated areas of the house. They can be made from a variety of materials available in your home, such as pieces of cloth, paper, cardboard, plant fibers and even insulation materials.

Look for signs of debris or building materials in hidden areas of your home, as mice often use these materials to build their nests.

That said, mouse nests can be difficult to spot, as they are often well concealed. However, you may notice areas where mice frequently move in and out, which may indicate the proximity of a nest.

If you find a mouse nest, it’s likely that the infestation is already well established. It’s important to take immediate action to eliminate mice and prevent their return, by thoroughly cleaning affected areas and identifying and sealing potential entry points.

Les souris sont agiles!

8. Odors

Mice often leave distinct odors in their environment. Mouse urine, for one, has a strong ammonia odor that becomes more pronounced as it accumulates. You may notice this odor in areas where mice urinate regularly, such as along walls or near nesting areas.

Mouse droppings, as discussed earlier, can also give off an unpleasant odor, especially when they start to decompose. If you notice a decomposing or unusual odor in certain parts of your home, this may indicate a mouse infestation.

Another example is the odor of a dead mouse, which smells bad because of the chemical compounds released. Although odors aren’t always the most obvious sign of a mouse infestation, they can be a useful indicator, especially when combined with the signs seen together before.

How do you know if you have one mouse or if it’s a mouse infestation

It’s always a bit tricky to identify the presence of a single mouse or whether it’s an invasion. In general, an infestation can be spotted by the larger quantity of droppings, clustered in corners, behind appliances and along passageways. Signs of activity will be more prominent: you’ll hear scratching noises more often, and more regular scampering. Be more attentive at night when you can make these observations.

If it’s a mouse infestation, be aware that we’re talking about a really serious problem and that an exterminator should be called in urgently. We’re used to intervening very quickly, precisely to limit the damage as quickly as possible.

Where do mice hide during the day?

Where they can’t be found! Since mice are nocturnal, they look for quiet, dark, predator-proof places to rest during the day. In the home, this means:

  • Behind household appliances, because they’re perfect refuges thanks to the heat they give off, and because there are wires to nibble on;
  • In walls and ceilings, where they can climb undisturbed;
  • Under sinks and washbasins, because the humidity and access to potential water leaks is attractive to them;
  • In piles of clothes, where it’s warm;
  • In attics or basements to be safe from human activity.

Les souris sont des animaux nocturnes

Reacting to a mouse infestation in your home

A mouse invasion can pose health and property risks, so it’s essential to take a proactive approach to solving this problem. When you identify signs of rodents in your home, it’s essential to react quickly. Mice can cause considerable property damage by nibbling on electrical wiring, insulation, furniture and building materials.

What’s more, mice transmit diseases such as leptospirosis, salmonellosis, 0and hantavirus. By acting quickly, you can minimize the health risks and property damage caused by mice.

What to do if you have a mouse in the house?

When faced with a mouse infestation, you have several options for getting rid of them. You can call in a residential exterminator who will be able to identify the extent of the infestation and apply appropriate methods to eliminate the mice. Professionals can use mouse baits, traps or suitable repellents to solve the problem effectively.

If you prefer to take a DIY approach, you can use mouse traps, natural repellents such as peppermint or mint essential oil, and exclusion measures to keep mice out of your home. You’ll also need to decontaminate your home after the mice have left. That’s why professionals are much better suited to dealing with this kind of situation.

A mouse problem? Make it Elite Pest Control’s business!

As you’ve seen, a mouse-infested home can represent a real problem, both in terms of health risks and property damage. It’s crucial to be vigilant and to react quickly to eliminate these pests from your environment.

At Elite Pest Control, we understand the importance of rapid, effective intervention. Our experienced professionals are trained to identify the extent of the infestation, implement appropriate control measures and offer customized solutions to protect your home.

We use proven methods and quality products to eliminate mice safely and effectively. Our aim is to provide you with a healthy, pest-free environment, and to prevent any recurrence. Contact us now for a fast, discreet and expert intervention!

Pascal Rock
Pascal Rock  
Director, Elite Pest Control
Founder and mainstay of Elite Pest Control, Pascal Rock has embodied expertise and dedication for over a decade. His training, acquired with expert mentors in extermination and pest decontamination, has shaped an outstanding professional. Under his leadership, a team of six seasoned technicians deploys the very best pest control strategies. Together, they ensure the peace of mind and safety of residents and professionals from Montreal to Quebec City, by offering fast, effective interventions, available at all times.