Here is a review about crawl space pest control by Parker Eco Pest Control which serves Edmonds and the Seattle area:

"We have been using Parker Eco Pest Control for the past 2 years. We had a coming and going rat problem that would seem to be solved and then come back. After a couple of visits to trap and kill the rats sneaking under our foundation, we finally realized we needed to do a lot more to prevent these furry devils from coming back. The Parkers explained to us that rats mark and scent their territory, and other rats can smell that mark and know it is a safe place to come stay. They ended up doing an enzyme killing fog in our foundation/crawl space that was safe for our pets and us (it smelled like very strong laundry detergent, a little intense during the treatment but fine afterwards). They then dug out of the side of our old foundation and installed a trench and screen along the side. We have not had a rat since!!! They have follow up twice to ask whether we have heard or seen anything. Their prices are competitive, and their technicians are very nice and explain everything in simple terms."

Here is the link to the review: https://maps.app.goo.gl/qZkUtWMfVbKuZuHf7