When the cool nights of fall arrive in the Treasure Valley, mice start looking for new places to nest. Homes in Nampa, Boise, and Meridian become prime targets as temperatures dip and food becomes harder to find outdoors. This seasonal migration—sometimes called “mouse season”—leads to a noticeable uptick in rodent calls across the valley from September through early winter.
Cold Nights Drive Rodents In
Mice are opportunistic and highly sensitive to changes in temperature. Even a few chilly nights can send them searching for warmth. Garages, crawl spaces, attics, and basements offer shelter, while pantries and kitchens provide an easy food supply. Once inside, they can establish breeding populations quickly, leading to ongoing infestations if not addressed early.
Telltale Signs of Mice
Homeowners often hear or see hints of mouse activity before spotting the rodents themselves. Key signs include:
- Droppings – Small, dark, rice-shaped pellets found along walls, near food storage, or in cabinets.
- Gnaw marks – Chewing damage on food packaging, wires, and even structural wood.
- Rub marks – Oily smudges along baseboards or entry points caused by mice repeatedly brushing their bodies against surfaces.
- Sounds at night – Scratching, scurrying, or gnawing noises in ceilings, walls, or crawl spaces.
- Nest material – Shredded paper, fabric, or insulation tucked into hidden corners.
Recognizing these early helps prevent a small intrusion from turning into a larger colony.
Where Mice Hide in Treasure Valley Homes
- Garages – Clutter, stored pet food, and unsealed doors make garages a frequent entry point.
- Crawl spaces – Provide dark, humid shelter and direct access to wall voids.
- Attics – Warm, insulated areas are perfect nesting sites for mice once they climb up siding or utility lines.
- Kitchens and pantries – Food attracts rodents once they’re inside, leading them to gnaw through packaging.
Entry Points: Smaller Than You Think
Mice only need a gap of ¼ inch—about the size of a pencil—to squeeze inside. Common access points include:
- Gaps under garage doors or weatherstripping.
- Utility line penetrations for plumbing, cable, or gas.
- Cracks in foundations or siding.
- Vents that lack screening.
This is why thorough inspection and exclusion are as important as trapping.
Sanitation and Exclusion First
Prevention begins with making your home less attractive to rodents:
- Seal all gaps ¼ inch and larger with steel wool, hardware cloth, or rodent-proof materials.
- Store food securely in sealed containers, including pet food.
- Declutter storage areas like garages and basements to reduce hiding spots.
- Maintain your yard by trimming back vegetation and keeping firewood stacks away from siding.
Professional Baiting and Trapping Plans
When signs of activity are already present, a professional service is the fastest path to control. A typical treatment plan includes:
- Inspection – Identify entry points, hotspots, and nesting areas.
- Interior trapping – Snap traps or multi-catch stations placed in active pathways for immediate reduction.
- Exterior bait stations – Placed around the perimeter to reduce pressure and prevent new intruders.
- Exclusion recommendations – Documenting gaps and structural fixes that will prevent re-entry.
- Timeline – Most infestations require 2–3 visits over 2–4 weeks to bring activity under control, followed by ongoing monitoring if needed.
Why Speed Matters
A single pair of mice can produce a dozen litters per year, with each litter containing 5–6 young. That means a seemingly minor issue in October can turn into a serious infestation by December if not acted on quickly. Taking fast action—through sanitation, exclusion, and professional treatment—saves both stress and long-term cost.