Hearing Scratching in Your Walls at Night?
It is 2 AM. The house is quiet. Then you hear it: a faint scratching, scurrying, or gnawing sound coming from inside your walls. You are not imagining it. That sound is almost certainly mice.
As temperatures drop across Calgary every October and November, mice search for warmth, food, and shelter. Your home, with its insulated walls, hidden voids, and easy access to crumbs, is exactly what they are looking for.
The bad news: a single pregnant female mouse can produce up to 60 offspring in a single season. The problem you hear today can become an infestation you smell, see, and breathe within weeks.
The good news: mice are one of the easiest pest problems to eliminate quickly when you act fast. This guide covers everything Calgary homeowners need to know, from identifying the signs to getting rid of mice for good.
Need help right now? Call Calgary Pest Guard at (825) 760-5364 for same-day mouse removal, or book an appointment online in under two minutes.
7 Signs You Have Mice in Your Walls
Mice are nocturnal and secretive. You will almost never see one during the day. But they leave behind clear evidence if you know what to look for:
- Scratching or scurrying sounds at night — The #1 sign. Mice are most active between dusk and dawn. You will hear them moving inside walls, ceilings, and under floors.
- Droppings near baseboards, pantries, and under sinks — Mouse droppings are dark, rice-sized (about 6 mm), and pointed at both ends.
- Gnaw marks on wires, wood, and food packaging — Mice constantly chew to keep their teeth filed down. Look for small, rough-edged holes in cardboard boxes.
- A musky, ammonia-like smell — Mouse urine builds up over time, especially in enclosed wall cavities. The smell is unmistakable.
- Greasy rub marks along baseboards and walls — Mice travel the same paths repeatedly. Their bodies leave dark, oily smudges on surfaces they brush against.
- Nests made of shredded paper, fabric, or insulation — Check hidden areas: behind appliances, inside storage boxes, and in wall voids.
- Your pet is obsessed with a specific wall — Dogs and cats can hear and smell mice inside walls long before you notice anything.
If you notice even two of these signs, you already have an active infestation. The time to act is now, not next month.
Why Mice Enter Calgary Homes in Winter
Calgary's winters are brutal. Temperatures regularly plunge below -30°C. Mice, which are native to fields and grasslands, cannot survive outdoors once the ground freezes and snow covers their food sources.
Your home offers everything a mouse needs to survive winter:
- Warmth — Insulated wall cavities stay above freezing even in the coldest months.
- Food — A single crumb under your stove can feed a mouse for a day.
- Water — Condensation on pipes and leaky faucets provide all the water they need.
- Shelter from predators — Cats, owls, and foxes cannot reach mice inside your walls.
Mice can squeeze through gaps as small as a pencil (6 mm wide). They enter homes through:
- Gaps around pipes and utility lines entering the foundation
- Cracks in the foundation or siding
- Unsealed gaps around doors and windows
- Vents and weep holes without proper screening
- Attached garage doors with worn weather stripping
Once inside, they nest in wall voids, attics, and behind kitchen cabinets, where they are nearly impossible to reach without professional tools.
The Real Danger of Mice in Your Walls
Most homeowners underestimate how dangerous a mouse infestation is. This is not just a nuisance. Mice in your walls are a genuine health and safety hazard:
Health Risks
- Hantavirus — Spread through mouse droppings and urine. Can cause severe respiratory illness.
- Salmonella — Mice contaminate food surfaces with their feces, causing food poisoning.
- Allergies and asthma — Mouse dander and urine particles circulate through your home's air, triggering respiratory issues, especially in children.
- Lyme disease and ticks — Mice carry ticks that spread Lyme disease to humans and pets.
Property Damage
- House fires — Mice chew on electrical wiring inside walls. This is a leading cause of unexplained house fires in Canada.
- Structural damage — Mice tunnel through insulation, drywall, and wooden studs, weakening your home's structure.
- Contaminated insulation — Mouse urine and droppings saturate insulation, requiring costly removal and replacement.
- Chewed plumbing — Mice gnaw on plastic pipes, causing hidden leaks and water damage.
A mouse infestation that costs $300 to eliminate today can cost $5,000+ in repairs if left untreated for a few months.
DIY vs. Professional Mouse Removal: What Actually Works
Why DIY Usually Fails
Hardware store traps and poison seem like a cheap fix, but they rarely solve the problem:
- Traps catch the mice you can see, not the ones inside your walls. The mice you trap are a tiny fraction of the total population.
- Poison kills mice inside wall voids, where their bodies decompose and create a horrific smell that lasts for weeks.
- DIY methods do not seal entry points. New mice enter as fast as you trap the old ones.
- Mice reproduce faster than you can trap them. A female mouse has 5-10 pups every 3 weeks.
Most homeowners who try DIY spend $100+ on traps and poison over several months, only to eventually call a professional anyway.
What Professional Mouse Removal Includes
When you hire Calgary Pest Guard, you get a complete solution:
- Full interior and exterior inspection — We find every entry point, nesting site, and travel path.
- Strategic trap placement — Professional-grade traps placed in the exact locations mice travel, not just where you see them.
- Exclusion and sealing — We seal every entry point with rodent-proof materials so mice cannot get back in.
- Monitoring and follow-up — We check traps and remove dead mice so you never smell them.
- Sanitation advice — We help you clean contaminated areas safely.
- 100% guarantee — If mice return within your warranty period, we come back at no cost.
Professional mouse removal in Calgary starts at $300. That is less than the cost of replacing contaminated insulation in a single wall cavity.
How to Prevent Mice from Entering Your Home
Whether you have had mice before or want to keep them out, here are the most effective prevention steps:
Seal Every Entry Point
- Fill gaps around pipes with steel wool and caulk (mice cannot chew through steel wool).
- Install door sweeps on exterior doors, including the garage.
- Screen vents and weep holes with 1/4-inch hardware cloth.
- Repair cracked foundation and siding before winter.
Eliminate Food Sources
- Store all food in sealed glass or metal containers.
- Clean under appliances regularly, especially the stove and fridge.
- Keep pet food in sealed containers and do not leave it out overnight.
- Take out garbage daily and use a bin with a tight lid.
Remove Nesting Materials
- Store cardboard boxes off the floor and away from walls.
- Keep firewood at least 20 feet from your home's exterior.
- Trim vegetation away from the foundation.
- Declutter storage areas, especially basements and attics.
Schedule a Pre-Winter Inspection
The single most effective step is a professional inspection before the first hard frost. Calgary Pest Guard will find and seal entry points before mice ever enter your home.
Mouse Removal Cost in Calgary
| Service | Starting Price | |---|---| | Residential mouse removal (1-2 visits) | $300 | | Full home exclusion and sealing | $450+ | | Commercial rodent control program | Custom quote | | Attic/crawlspace cleanup | $600+ |
All our mouse removal services include a written guarantee. If mice return within the warranty period, we re-treat at no additional cost.
Frequently Asked Questions
Can mice live inside my walls without coming into my house?
Yes, and this is extremely common. Mice can live entirely inside wall voids, traveling through the studs and insulation, and only emerge at night to forage for food. You may never see a mouse but still have a significant infestation inside your walls.
How fast can Calgary Pest Guard come out?
We offer same-day and next-day appointments throughout Calgary and surrounding areas. Call (825) 760-5364 before noon and we can often be at your home the same day.
Is mouse removal safe for my kids and pets?
Absolutely. We use tamper-resistant bait stations and traps placed in locations pets and children cannot reach. All our products are Health Canada-approved and applied by licensed technicians.
How long does it take to get rid of mice?
Most infestations are resolved within 5 to 14 days. Severe infestations may take up to 3 weeks with follow-up visits. We will give you a clear timeline during your inspection.
Do you serve my area?
We serve all of Calgary, Airdrie, Cochrane, Chestermere, Okotoks, Strathmore, High River, and surrounding communities in Southern Alberta.
Do Not Wait. Mice Multiply Fast.
Every day you wait, the problem gets worse. A single mouse today can be 30 mice by next month. The scratching you hear at night is not going to stop on its own.
Call Calgary Pest Guard now at (825) 760-5364 or book an appointment online. Licensed, insured, and 100% guaranteed. Same-day service available across Calgary and Southern Alberta.