Spokane does not have the year-round insect pressure of Florida or Texas, and that is exactly why its pest problems catch people off guard. The Inland Northwest has hot, dry summers, cold winters with real snow, and a river that runs right through downtown. Pests here are seasonal and opportunistic: they move indoors when the weather turns, and they exploit the quirks of the city's older housing.
Four seasons, four sets of pests
Spring thaw wakes up carpenter ants in damp wood and sends pavement ants into kitchens. Summer is the season of yellowjackets, paper wasps and, along the Spokane River and in the Valley, mosquitoes. As nights cool in September and October, mice, spiders and boxelder bugs press against sun-warmed walls looking for a way in. Winter drives deer mice and house mice into garages, crawl spaces and attics, and even Norway rats appear in some older areas. Wildfire smoke seasons also leave some homeowners keeping windows closed, which helps keep insects out but not those that have already settled in.
Housing stock that shapes the problem
- Craftsman and Tudor homes on the South Hill, in Manito and in Browne's Addition often have basements with stone or concrete foundations, old coal chutes and gaps around utility lines.
- Brick and wood-frame houses in Perry District, Logan and Hillyard have older siding and weathered trim that harbor ants and spiders.
- Newer developments in the Valley, on the North Side and toward Liberty Lake border open ground and farmland where mice and voles are active.
- Apartments near Gonzaga, downtown and the Medical District occasionally struggle with German cockroaches and bed bugs.
Common pests and what they signal
Carpenter ants usually mean moisture-damaged wood, such as a leaky window frame, rotting fascia or a poorly flashed deck. Mice indicate gaps at the foundation or garage. Spiders, including hobo spiders and black widows in the occasional warm corner, come with the insects they eat. Termites are far less of a worry here than in warmer parts of the country, although dampwood species occasionally appear in very wet or decaying wood. Fleas show up where pets or wildlife roam, and bed bugs travel with people everywhere.
What a professional does
- Walks the exterior to check sealing, drainage, firewood piles, vegetation and eave condition.
- Inspects the basement, attic and garage for droppings, nests and moisture.
- Applies targeted treatments to foundations, eaves and entry points and sets baits or traps as needed.
- Recommends repairs such as caulking, door sweeps and gutter fixes.
Getting ready for the cold months
Before the first hard frost, seal cracks around the foundation, install door sweeps on the garage, screen vents with fine mesh, and store firewood away from the house. Clean gutters so snowmelt does not soak the siding. Check weatherstripping and attic vents. This simple routine, done in September, prevents most winter calls.
How to reach a pro
PestMinistry is a phone referral service, not a pest control company. Call (844) 725-1661, tell us what is going on at your Spokane property, and we will connect you with a licensed independent provider from our network who can inspect and treat.
Do Spokane winters kill pests?
Cold slows outdoor insects but does not stop those living inside heated buildings, and rodents are more active in winter.
Why do I have so many boxelder bugs in fall?
They gather on warm, sunny walls before overwintering and sometimes slip indoors through gaps.
Are hobo spiders a serious threat?
Their reputation is worse than the evidence supports, but any spider bite that worsens should be checked by a doctor.
When is the best time to book a visit?
Spring for ants and wasps, and early fall to keep mice and spiders from coming inside.