| Clue | What it reveals | Priority action |
|---|---|---|
| Small elongated droppings near food | Regular traffic in kitchen or pantry | Entry-point inspection and sanitation |
| Running sounds in ceiling or walls at night | Nesting or travel inside cavities | Map the routes and seal access |
| Chewed cables, plastic or insulation | Constant gnawing: fire risk | Fast intervention recommended |
| Burrows or runs along the foundation | Direct access from outside | Outdoor exclusion and yard upkeep |
Why they pick your house
As cold approaches, rodents want three things: warmth, food and a quiet shelter to nest. A house offers all three, and an adult mouse squeezes through an opening the size of a dime.
Classic entry doors: warped garage-door seals, unsealed pipe and cable penetrations, poorly screened vents, sliding-patio gaps, and the junction between foundation and exterior cladding.
Understanding this flips the approach: the question is less “how do we eliminate them” than “how do we make the building impenetrable”. Any strategy focused only on traps spins in circles while the accesses stay open.
Reading the clues and gauging the scale
Droppings tell the story: fresh and dark means current activity; old and dusty means past presence. Their concentration marks travel zones: behind the stove, under the sink, along pantry baseboards.
Nighttime noises (light running overhead, gnawing behind a wall), pinpoint routes. Mark those points on a floor plan: that’s the map the provider will use to place traps and seals.
Mind material damage: chewed electrical wires are not cosmetic trivia, they’re a recognised fire hazard. Confirmed presence in walls or ceilings deserves fast action, not passive observation.
The method that lasts: exclusion, sanitation, control
Pillar one: exclusion. Seal openings with materials rodents can’t easily chew: metal mesh, cement, metal kick plates under thresholds. Walk the entire perimeter, including the roofline for squirrels and climbing rats.
Pillar two: sanitation. Food in sealed containers, dishes washed the same evening, lidded bins, restraint in feeding neighbourhood birds, and a tidy yard: firewood stored apart, vegetation trimmed back from walls. Denied resources, rodents move on.
Pillar three: controlling residual populations (mechanical traps placed along mapped routes. As for chemical rodenticides, their use is regulated: around children, pets or wildlife, entrust baiting to an authorised professional whose applicators hold the required permits and certificates, operating under a verified RBQ-licenced contractor where the scope of work requires it. And let’s be honest: no serious provider promises instant total elimination), persistence is part of the plan.
Special cases: buildings and property purchases
In a rental building, the logic scales up: rodents travel between units through common cavities. Treating one apartment without examining common areas, the yard and utility rooms is bailing the ocean with a teaspoon.
For buyers, a careful pre-purchase inspection notes the clues: droppings in attic or crawl space, disturbed insulation, unsealed openings. Those findings belong at the negotiation table, and their fixes get scheduled before move-in.
In both cases, success rests on the same discipline: map, exclude, sanitize, then control with follow-up. Less spectacular than a massive bait campaign, but it’s the only approach that holds through the following winter.
Verified and sourced
Verified on September 27, 2026
Official sources
What these numbers do not cover
Preventing entry means sealing access points; no treatment or price is quoted here.