Common Household Pests in Spokane, WA (by Season)

Most pest problems in Spokane homes are seasonal, and nearly every pest on this list starts outside. Knowing what shows up when, and how it gets in, is most of the battle. This guide covers six of the most common: ants, wasps and yellow jackets, earwigs, spiders, boxelder bugs and mice, with what you can do yourself and when perimeter pest control in Spokane makes sense.

Which pests show up in Spokane each season?

Spring and summer bring ants, then wasps and yellow jackets as their nests grow. Earwigs peak in summer around damp beds and foundations. Fall is when spiders, boxelder bugs and mice move toward the house, looking for a way in before winter.

Why do ants come inside in spring and summer?

Ants come in looking for food and water. As the ground warms in spring, colonies get active and send workers out foraging, and a trail of crumbs or a dripping pipe is an easy find. Trails along driveways, sidewalks and foundations are a common sight in Spokane yards all summer.

What helps: wipe up crumbs and sticky spills, keep food and pet food sealed, fix drips and seal the gaps where trails come in. Killing the ants on the counter rarely ends it, because the nest sending them is outside or tucked into a wall. A treated band along the foundation stops more of the foragers before they reach the kitchen. See ant control in Spokane.

When are wasps and yellow jackets worst in Spokane?

Late summer. Each nest is founded in spring by one queen working alone. Her workers expand it through the summer, and by August and September it's at full size. That's when yellow jackets crowd patios, garbage cans and picnic tables looking for food, and when they're most defensive around the nest.

Look for paper nests under eaves, deck rails and play structures, and for a steady stream of yellow jackets going in and out of one hole in the ground. Yellow jackets often nest in old rodent burrows and other cavities in lawns and beds, which makes those nests easy to mow over or step on. A hard freeze ends the colony. Only new queens survive the winter, and old nests aren't reused.

What helps: spot nests early in the season while they're small, and keep garbage, recycling and pet food covered. For nests near doors, walkways or play areas, see wasp and yellow jacket control.

Why are there earwigs around your foundation?

Earwigs like damp, dark hiding spots. They spend the day under mulch, stones, pots, boards and dense groundcover and come out at night. In summer, watered flower beds against the house are ideal habitat, and earwigs wander inside through gaps around doors, windows and the foundation.

They look alarming but are mostly a nuisance. They can pinch, but they aren't dangerous, and despite the old tale, they don't seek out people's ears. Outdoors they can chew on seedlings and soft plants.

What helps: dry out the zone next to the house. Pull mulch back a few inches from the foundation, clear boards and clutter off the ground, fix leaky spigots and adjust sprinklers that spray the siding (our sprinkler guide covers head adjustments). A perimeter treatment along the foundation targets the zone where they gather.

Why do you see more spiders in late summer and fall?

Spiders live around your house all year. By late summer and early fall most have reached adult size, and the males start roaming to find mates. That's when they end up in basements, garages, window wells and bathtubs, where you notice them.

Spiders follow their food. Porch lights draw insects and insects draw spiders, so fewer bugs around the house generally means fewer spiders.

What helps: knock down webs and egg sacs, cut back plants touching the siding and seal gaps around windows, doors and utility lines. Yellow “bug light” bulbs in outdoor fixtures draw fewer insects. A perimeter treatment along the foundation, entry points and the beds against the house does the heavy lifting. As John H. put it in a Google review: “Haven't seen spiders since!” See spider control in Spokane.

Why do boxelder bugs cover sunny walls in fall?

Boxelder bugs are black insects with red-orange markings, about half an inch long. They feed on the seeds of boxelder trees and some maples during summer. In fall they gather on warm, sunny walls, usually on the south and west sides of the house, looking for a sheltered place to spend the winter. Some find their way inside through cracks and gaps and reappear on warm winter days.

They rarely bite, and they don't damage the house or breed indoors, but they can stain walls and fabric when crushed. Vacuum them up instead of squashing them.

What helps: seal cracks around windows, doors, siding and utility lines before fall, and repair torn window screens. Treating the outside walls where they gather, before they find a way in, is the best timing. Mention them when you ask about pest control for your home.

When do mice move into Spokane homes?

Fall and winter. As temperatures drop, mice look for warmth, shelter and food, and houses that back onto fields or empty lots tend to see them first. A gap of about a quarter inch is enough for a mouse, so the small openings around pipes, wires, vents and garage doors are all ways in.

Signs include small dark droppings in drawers, cupboards or along walls, chewed packaging and scratching in the walls or ceiling at night.

What helps: seal gaps with steel wool or hardware cloth and caulk. Replace worn garage door seals and door sweeps. Store pet food, bird seed and grass seed in sealed containers, and keep firewood stacked away from the house. See mouse control in Spokane.

How does perimeter pest control keep pests out?

Most of these pests start outside and come in through the same few places. Perimeter pest control puts a treated barrier around the outside of the building, focused on:

• The foundation, where cracks and openings give easy access
• Entry points like doors, windows and the gaps around utility lines
• Landscaping against the house, where mulch, flower beds and overgrown plants give pests shelter

Treating the outside cuts down on the need for broad treatments inside your home, and regular treatments keep the barrier working as each season's pests change. Clearing leaves and debris away from the house helps too, which is one reason a fall yard cleanup pays off.

If you're seeing any of these pests, Automated Lawn & Pest Control's perimeter pest control covers homes and businesses in Spokane, Spokane Valley and nearby communities. Request a free quote or call (509) 818-1831 and tell us what you're seeing and where.