Home › Pests We Treat › Mice
Identification Snapshot
| Colour | Light brown to grey, with a lighter grey-white belly |
| Size | 12–20 cm including tail (body roughly the size of a thumb) |
| Description | Large ears, pointed snout, long thin tail, droppings about the size of a grain of rice |
How to Identify Mice
The house mouse (Mus musculus) is the mouse most commonly found in Montreal homes. They’re small — usually no more than 8 cm long, not counting the tail — with large rounded ears, a pointed nose, and a thin, semi-hairless tail that’s about as long as the body. Their fur ranges from light brown to grey. Because they’re excellent climbers and can squeeze through gaps as small as a dime, they’re often mistaken for having “come from nowhere” when really they’ve found a small crack, vent, or gap around a pipe.
Key Signs of a Mouse Infestation
- Droppings: small, dark, rice-grain-sized pellets, often clustered near food sources, along baseboards, or inside cupboards
- Gnaw marks: on food packaging, wires, wood, and baseboards — mice need to gnaw constantly to keep their teeth short
- Scratching or scurrying sounds: especially at night, in walls, ceilings, or under floors
- Grease marks: dark smudges along walls and baseboards where mice repeatedly travel the same routes
- Nesting materials: shredded paper, fabric, or insulation gathered in hidden corners, drawers, or behind appliances
- A stale, musky odour: especially noticeable in enclosed spaces like cupboards or crawl spaces
What to Do If You Find Mice
Do
- Seal any food in airtight containers
- Clean up crumbs and spills promptly
- Check under sinks, behind appliances, and in storage areas for droppings
- Note where you’re seeing activity — it helps us target treatment faster
- Call a licensed professional as soon as you notice signs
Don’t
- Rely on a single trap and assume the problem is solved — one mouse is rarely the only one
- Handle droppings or nesting material with bare hands
- Block entry points without knowing where mice are already nesting inside
- Use poison baits without professional guidance — this can create odour problems
How to Prevent Mice
- Seal gaps around pipes, vents, and the foundation — a mouse only needs an opening the width of a pencil
- Store dry food, pet food, and birdseed in sealed containers, off the floor
- Keep basements, garages, and storage areas decluttered so mice have fewer places to nest
- Trim back vegetation and stacked firewood away from the exterior walls
- Repair damaged weatherstripping and door sweeps, especially on garage and exterior doors
- Schedule a seasonal inspection, particularly heading into fall when mice look for a warm place to overwinter
Habitat, Diet & Behaviour
House mice are highly adaptable and thrive close to people — in walls, attics, basements, and cluttered storage areas. They’re most active at night and can produce a new litter every three weeks, which is why a small mouse problem can turn into a serious infestation in a matter of months. Mice are omnivores but prefer grains, seeds, and pet food; they need very little water to survive, getting most of what they need from food.
Frequently Asked Questions
How do I know if it’s mice or rats?
Mouse droppings are smaller (about the size of a grain of rice) and pointed at the ends, while rat droppings are larger and more capsule-shaped. Mice also leave smaller gnaw marks and tend to nest closer to food sources indoors.
Can mice really fit through such small gaps?
Yes. A house mouse can squeeze through an opening as small as 6 mm — roughly the width of a pencil — because their skeletons are flexible enough to compress their body.
Are mice dangerous?
Mice can contaminate food and surfaces with droppings and urine, trigger allergies and asthma, and gnaw through electrical wiring, which creates a fire risk. They can also carry parasites like fleas and mites into your home.
How fast can Optima get rid of a mouse problem?
Every situation is different, but most mouse jobs start with an inspection to find entry points and nesting activity, followed by targeted trapping or baiting and exclusion work to seal entry points. We’ll walk you through the expected timeline during your free estimate.
Do I need to leave my home during treatment?
Typically no — our mouse control methods are designed to be safe for occupied homes. We’ll let you know if any specific precautions apply to your situation.
Why Choose Optima Extermination
Fast, discreet, and reliable pest control solutions designed to eliminate problems and keep them from coming back.
Licensed Experts
Our trained and certified technicians use safe, proven methods to handle every pest problem professionally and effectively.
Safe & Effective Treatments
We use industry-approved products and techniques that are safe for your home, family, and environment.
Fair & Transparent Pricing
Clear estimates with no hidden fees — just honest pricing and reliable service you can trust.
Fast Response
We act quickly to assess and treat infestations, helping you regain control of your space without delay.
Proven Results
Our methods are designed to eliminate pests at the source and reduce the risk of future infestations.
Discreet Service
We respect your privacy with low-profile, professional service for homes, apartments, and businesses.
Client Reviews
Real feedback from Optima Extermination customers across Montreal.
“What an amazing experience with Optima Extermination! The team was professional, knowledgeable, punctual, and incredibly thorough. They took the time to explain everything clearly, answered all of our questions, and made the entire process easy and stress-free. As soon as I called for the service, they were at my door the next morning!”
— Leah D.
“Incredible service from Optima! I called on Sunday morning and by mid afternoon the technician was here to deal with my large wasp infestation. Not only did he take care of the problem, he reassured me that he would come back promptly if I needed further assistance. I highly recommend this company.”
— Dale M.
“We had a great experience with this exterminator. The service was excellent, professional, and reliable. They took the time to explain the problem, provided helpful advice, and made sure we understood the best steps to take. Highly recommended.”
— Vanessa R.
“I called about a mouse problem in my basement, and they came the very next day. Within just two days, the mice were gone! He politely explained the procedure, answered all of my questions, and was friendly and professional throughout. 10 stars!!!!”
— Mel DS.
“My neighbor had a bed bug problem. I called a few extermination companies for my condo as well. In the end, I chose Optima Extermination, and it turned out to be a great choice. The welcome was very warm, the work started right away, and the products used proved very effective. What surprised me most was how friendly and attentive Mr. Gil and his team were, during and after the work.”
— Thanh N.
Residential
Mice in your home? We’ll find where they’re getting in and make sure they don’t come back.
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Protect your business from rodent activity with a discreet, professional inspection and treatment plan.
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