Ask what they inspect, whether they'll look at the crawl space, and how they treat each pest. The answers separate a plan from a spray.
Start with the crawl space
A pest problem in Corvallis is usually a moisture problem, and moisture problems live in the crawl space. A damp crawl space feeds carpenter ants, dampwood termites, silverfish, sowbugs, springtails, and spiders all at once. So the single most useful question you can ask a pest control company is whether they will inspect the crawl space, and what they do about moisture.
A company that quotes a price over the phone without looking under the house is selling a spray, not a plan. In this climate, that spray will disappoint by the next wet season.
Ask how they treat each pest, specifically
Different pests need different methods, and the answers should be concrete. Carpenter ants: locate the parent nest, use non-repellent products, and correct the moisture, not a repellent spray. German cockroaches: gel bait and a growth regulator, not a fogger. Rodents: trapping plus exclusion and crawl space sealing, not scattered bait. Yellowjackets: treat the nest at the entrance with protective gear. Moisture pests: fix the crawl space, not just the baseboards.
A company that describes the same treatment for every pest has not thought about yours.
Ask about the moisture
This is the Corvallis-specific question, and most people never ask it. Because so much of the local pest pressure traces back to damp crawl spaces and poor drainage, a good local company should have opinions about your vapor barrier, your foundation vents, your gutters, and your grading.
If the answer is only about which chemical they will spray, and never about the water, they are treating the symptom. Ask what they would do about the moisture, and whether they coordinate crawl space work.
Ask what happens after
Most pest work here is not one visit. Ask how follow-up is scheduled, what triggers a return, and how they confirm the problem stopped rather than slowed. For rodents specifically, ask whether exclusion is included or an add-on, because trapping without sealing the crawl space is a subscription rather than a solution.
For bed bugs and German cockroaches, ask about the second visit. Eggs hatch after the first treatment, and skipping the follow-up is the most common reason a job appears to fail.
Get clear on the details
Understand what is included, how recurring service is billed, and what you are expected to do before a visit. Ask about re-entry times if you have kids or pets. Get it in writing. If you own a rental near OSU or run a business downtown, ask what treatment records you receive.
A local pro should have opinions about your address, not a template: whether you are on a damp crawl space, whether the forest or field edge behind you is a rodent source, whether the gutters are feeding the carpenter ants. Then call and describe exactly what you are seeing, where, and when. The more specific you are, the faster an experienced local exterminator can tell you what you are dealing with.
Call and connect with an experienced local exterminator.