Mice in the House: Who Should You Call?
Urgency: SoonUpdated 2026-08-31
Short answer
Seal entry points, remove food sources and set snap traps along walls. If you are still seeing activity after two weeks, or you hear activity inside walls or the attic, call a licensed pest control company. The permanent fix is exclusion — sealing every gap larger than about 6 mm — not repeated baiting.
Who to call: A licensed pest control company that does exclusion work, not just baiting.
What to do right now
- 1Store all food, including pet food, in sealed hard containers.
- 2Set snap traps perpendicular to walls where you see droppings.
- 3Seal gaps around pipes, dryer vents and the garage door sweep with steel wool and caulk.
- 4Clean droppings with a disinfectant spray, not a broom or vacuum, to avoid aerosolising contaminants.
Most likely causes
- Gaps at the building envelope
- A mouse fits through a hole the width of a pencil. Utility penetrations and garage doors are the usual routes.
- Autumn temperature drop
- GTA mouse calls spike in October and November as they move indoors.
- Accessible food and water
- Pet bowls, bird feeders, open compost and pantry packaging.
- Nearby construction
- Excavation next door displaces established populations into neighbouring homes.
What it typically costs in the GTA
$250–$500 for an initial pest control treatment with follow-up. $500–$2,000 for full exclusion work on a detached home. Attic insulation remediation after a heavy infestation runs $2,000–$6,000.
Ranges are typical market pricing for the Greater Toronto Area and vary with access, age of the home, and time of year. Always get the scope in writing before work starts.
Why baiting alone never works
Bait reduces the current population but changes nothing about why they got in. Without exclusion, the house repopulates from the same entry points within a season. Any pest company worth hiring will inspect the exterior and quote sealing work alongside treatment.
Signs it has reached the attic
Scratching overhead at night, droppings on insulation, and a musky smell mean the population has established above the ceiling. At that point insulation is usually contaminated and needs assessment.
Get the right pro on it
Describe the problem in your own words. We’ll work out which trade you need and connect you with suitable local pros. Free, no obligation.
Frequently asked questions
- How do I know if mice are gone?
- Place fresh droppings markers or flour patches in active areas. No new tracks or droppings for two weeks is a good sign.
- Are mice a health risk?
- Yes — droppings and urine contaminate food surfaces and insulation, and they chew wiring, which is a genuine fire risk.
- Do ultrasonic repellers work?
- There is no credible evidence they do. Sealing and trapping do.