Pest control in Washington

What to know about pest control in Washington

Washington's wet west side and dry east side give it a wide mix of pests. Carpenter ants and yellowjackets are familiar problems across the state, and many people worry about spiders that turn out to be harmless. Mice need care too, because of the illness they can carry.

Common pests in Washington

Washington State University Extension and the Washington State Department of Health describe these pests as common concerns for Washington homes.

• Carpenter ants. WSU says carpenter ants are pests because they often nest in homes. They do not eat wood, but they hollow it out for nests and sometimes weaken it. See companies that handle ants near you.
• Yellowjackets. WSU says yellowjackets are especially aggressive in late summer and fall. Nests in wall voids or attics are the most troublesome, since the wasps sometimes chew their way into rooms.
• Spiders. WSU scientists say the hobo spider does not deserve its scary reputation, and the brown recluse does not live naturally in the Northwest. Many spiders people find indoors in fall are harmless.
• Deer mice. The state health department says deer mice that carry hantavirus live throughout Washington. Air out closed spaces before cleaning, and do not sweep or vacuum droppings.

Who licenses pest control companies in Washington

The Washington State Department of Agriculture licenses commercial pesticide applicators, and it separately licenses structural pest inspectors. Its pesticide and structural pest inspector licensing page explains the license types. You can look up a person or a business with the department's license search.

How to check a company before you hire

1. Search the company and the technician by name in the department's license search.
2. If you need a wood-destroying insect inspection, for example when buying a home, ask whether the inspector holds a structural pest inspector license.
3. Ask which pest was found and how the treatment will work.
4. Get the treatment plan and any warranty in writing.
5. Read reviews from other Washington customers to see how the company handled follow-up visits.