Every autumn in Southern Ontario, the same migration happens: as nights turn cold, house mice — and in some neighbourhoods, Norway rats — look for a warm place to spend the winter, and your home is at the top of the list. A mouse can squeeze through a gap the width of a pencil. Countryside Pest Solutions provides rodent control in Guelph and across the region, built on the approach that works long-term: find how they’re getting in, remove the ones inside, and seal the building so they can’t come back — with kid- and pet-safe methods. No loose poison indoors, ever.
Signs of a Rodent Infestation
Mice and rats leave different evidence, and telling them apart helps us choose the right strategy:
- House mouse signs. Droppings are the giveaway — small, rod-shaped pellets about the size of a grain of rice, scattered along baseboards, inside cupboards, and in the back of drawers. Look for gnaw marks on food packaging and wiring, shredded nesting material in quiet corners, and a musky odour in enclosed spaces. You may hear light scratching in walls at night.
- Norway rat signs. Norway rats are ground-level burrowers — along foundations, under sheds and decks, and in crawl spaces. Look for burrow openings (5–8 cm across) in soil near the foundation, worn runways along walls, and larger, capsule-shaped droppings. Gnawed entry holes are bigger than a mouse hole, with rough, chewed edges around doors, vents, and utility penetrations.
- Roof rat signs. Less common in Ontario, but they do show up — roof rats are climbers that nest in attics and upper wall voids. Signs include droppings in the attic, gnaw marks on fascia and soffits, and noises overhead at night. Overhanging branches near the roofline invite them.
Fresh droppings are dark and soft; older ones dry out and turn grey — fresh signs mean an active population that needs addressing now.
Health and Property Risks
Rodents cause two kinds of damage: what they chew and what they contaminate. Their teeth never stop growing, so they gnaw constantly — on wiring (a genuine fire hazard), pipes, insulation, drywall, and framing. Shredded insulation and chewed vapour barriers also cut your home’s energy efficiency.
On the health side, mice and rats contaminate far more food than they eat, through droppings, urine, and hair. They can carry bacteria such as Salmonella and Leptospira, which is why any food packaging showing gnaw marks should be discarded, not salvaged. Their droppings and nesting materials can also trigger allergies and aggravate asthma, particularly in children. These risks are real — but completely manageable with prompt, professional action.
Our Rodent Treatment Process
Poison alone is not a rodent control strategy. Our process is built around exclusion:
- Full inspection, inside and out. We inspect the attic, basement, crawl space, garage, and the entire exterior — foundation, soffits, vents, doors, and utility penetrations — identifying the species and mapping every entry point. A house mouse needs only a 6 mm gap; rats need about 12 mm.
- Exclusion — sealing them out. This is the step that makes results last. We seal entry points with rodent-proof materials: steel wool and copper mesh packed into gaps, metal flashing and hardware cloth over vents, and door sweeps under doors. Mice can’t chew through properly installed steel mesh.
- Trapping and removal. For rodents already inside, we use snap traps in tamper-resistant stations along runways and in voids. Outdoors, we install locked, anchored bait stations around the perimeter where appropriate. We never place loose rodenticide inside a home with children or pets.
- Follow-up and monitoring. We return to check traps, confirm activity has stopped, and verify the exclusion work is holding. For properties near fields, ravines, or commercial areas, we can set up seasonal monitoring so new attempts are caught early.
Prevention Tips for Southern Ontario Homeowners
- Seal the building envelope. Walk your foundation in early fall and seal every gap larger than a pencil’s width with steel wool plus caulk, or hardware cloth for larger openings — especially where utilities and pipes enter.
- Mind your doors. Install brush-style door sweeps on exterior doors and make sure garage doors close fully — attached garages are the number-one mouse entry point.
- Store food in hard containers. Transfer dry goods and pet food into glass, metal, or heavy-duty plastic containers with tight lids — mice chew through bags and cardboard in minutes.
- Manage garbage and compost. Use bins with locking lids, keep them away from the house wall, and maintain compost bins properly — open compost is a rat attractant. Clean up fallen fruit and avoid leaving pet food outside overnight.
- Tidy the yard. Clear clutter, brush piles, and dense ground cover near the foundation. Store firewood 6 metres from the house and off the ground, and trim vines and branches away from the roofline.
Areas We Serve
Rodent pressure is heaviest where housing meets fields and ravines — which describes much of our service area every October. For pest control in Guelph and pest control in Kitchener-Waterloo, our fall schedule fills quickly, so early booking helps. We also provide rodent exclusion and trapping through pest control in Brantford, pest control in Elora, and pest control in Georgetown, Ontario. See our service area page for the full list, or contact us to book an inspection.
Frequently Asked Questions
How are mice getting into my house?
Through gaps you’d never notice — a house mouse fits through a 6 mm hole, about the diameter of a pencil. Common entries include gaps around pipes and cables, under garage doors, damaged vent screens, and where the foundation meets the siding.
Is rodent treatment safe with kids and pets in the house?
Yes. We never scatter loose poison indoors. Interior control uses snap traps inside tamper-resistant stations placed in voids and along runways, out of reach. Exterior bait stations are locked, anchored, and tamper-resistant.
How long does it take to get rid of mice?
Most house mouse jobs resolve in 2–4 weeks: trapping removes the interior population while exclusion stops reinforcements. Larger rat issues can take longer; we monitor until activity stops completely.
If I see one mouse, are there more?
Almost certainly. Mice are social and breed rapidly — a female can produce 5–10 litters per year — and where one found food and shelter, others will follow the same scent trails. Treat one sighting as an early warning.
Will the rodents come back after treatment?
Sealed entry points stay sealed — properly installed exclusion is permanent. New activity usually means a new gap has opened or exterior pressure is high, which is why we verify our work on follow-ups and offer seasonal monitoring for high-pressure properties.
Seal Them Out for Good — Before Winter Moves Them In
Fall is rodent season — the best time to act is before the first cold snap. Call (519) 239-5534 or hit the Request a Quote button to schedule an inspection. Safe for kids. Safe for pets. Tough on pests.