Ontario Fall Rodent Migration: Why Mice Move Indoors in October & How to Stop Them

## The Seasonal Shift: Why Southern Ontario Homes See Mice in Autumn

Every year as nighttime temperatures across Toronto, Mississauga, and the Greater Toronto Area dip below 10°C, house mice (*Mus musculus*) and deer mice experience a natural instinct to find warm, sheltered nesting sites with ready food access.

Your home’s heated basement, wall cavities, and attic represent an ideal winter sanctuary. Understanding how rodents navigate residential structures is the first step toward effective exclusion.

### 5 Early Warning Signs of Mouse Intrusion

1. **Dark, Rice-Sized Droppings:** Frequently found near kitchen baseboards, under sinks, or inside pantry corners. 2. **Shredded Insulation or Paper:** Rodents gather soft materials to construct subterranean nest pockets. 3. **Nocturnal Scratching Noises:** Scampering sounds in drywall or ceiling joists after dark. 4. **Grease Rub Marks:** Oily smudge lines along baseboards caused by rodent fur. 5. **Chewed Cables or Packaging:** Mice must continuously gnaw to wear down their rapidly growing incisors.

### Professional Exclusion Steps for Homeowners

- **Seal Foundation Gaps:** Inspect exterior brick weep holes, utility pipe entry points, and garage door bottom seals. Use galvanized steel mesh (1/4 inch) combined with exterior silicone caulk. - **Manage Outdoor Food Sources:** Keep bird seed stored in airtight metal bins, elevate firewood piles at least 18 inches off the ground, and clear fallen apples or garden waste. - **Maintain Clean Kitchen Counters:** Store grains, pet food, and flour in sealed glass or heavy plastic containers.

If you suspect an active rodent infestation, contact **K2PC Pest Control** for a 360° inspection and guaranteed exclusion sealing.