Native or introduced: why identification comes first in Washington
Most states let you treat every tree squirrel the same way. Washington does not. The Department of Fish and Wildlife lists the western gray squirrel as threatened, which means it cannot be hunted, trapped, or killed. It is also the biggest tree squirrel in the state at eighteen to twenty four inches, with a notably large bushy tail, so size and bulk are your first sorting tool. Eastern gray and eastern fox squirrels came from elsewhere. They are unclassified under state rules and may be trapped or killed year round with a hunting license, and they are the ones behind most attic complaints in Puget Sound neighborhoods. Douglas squirrels and red squirrels are natives too, smaller and often reddish or olive toned, common wherever conifers are. The practical takeaway is simple. Exclusion with a one way door is legal and effective regardless of which species you have, which is why it is the safest default here. Trapping requires you to be right about the animal, so unless the identification is certain, choose the method that does not depend on it.
The Washington litter calendar and when to seal
State guidance gives you the dates you need. WDFW describes one litter of two to four young from March through June, with a second litter in August or September for most species. Those two spans are when an attic may contain animals that cannot leave on their own. That leaves two workable windows. Late June through July is usually clean, after the first litter is mobile and before the second arrives. October through February is the other, and on the west side it is the harder one to work in because of rain. Plan repairs for the dry stretch and accept that removal happens when it happens. Silence is not evidence. An adult out foraging leaves a quiet attic behind, and pups too young to move make almost no sound during the day. The check that matters is a person with a light going into the space and looking, not a week of listening from the hallway. If a quote does not include that step during a litter window, ask why.
West side rot versus east side cold
Around 38 inches of rain a year and humidity near 73 percent shape the west side problem. In Seattle, Tacoma, Bellevue, and Vancouver, exterior trim stays wet enough for long enough that fascia softens, paint lifts, and galvanized vent screen corrodes. a squirrel does not need a hole to start, only a soft edge to brace against, so the low corners of the roof and the ends of soffit runs fail first. Spokane and the drier east side present a different pattern. Wood holds up better, but colder snaps below the 35F median winter low in our Washington city data concentrate animals indoors, and flying squirrels and red squirrels arrive as groups rather than singly. What sounds like one busy squirrel is often several small ones. Repair should follow the climate. On the west side, assume corrosion and use stainless or heavy aluminum, mechanically fastened. On the east side, focus the inspection on small overlooked gaps at ridge ends and vent boots, because a colony needs less of an opening than a fox squirrel does.
What a first inspection should cover
Expect most of the visit to happen outside. A competent operator walks the full perimeter and looks at the fascia and soffit joint, every gable end, the ridge, dormer seams, the chimney, and each vent, because squirrel entries are chewed joints rather than obvious holes. Then they go inside with a light and read the attic: runs pressed into insulation, cached cone scales, chew dust, and staining. Before quoting they should tell you the species, whether the date falls inside a litter window, and how many separate openings exist. In this state the species answer is not a curiosity, it determines which methods are lawful. Ask for the scope in writing. It should name the removal method, the material for each repair, and what happens to soiled insulation. Confirm that the follow up trip to pull the one way door and permanently close the hole is inside the price. That last visit is the one that ends the problem, and it is the one most often left out of a low headline number.
Comparing two quotes on a Washington house
Start with the entry count. If one company found five openings and the other found one, somebody did not walk the roof. Have the higher count show you each spot, and if they can, you have learned who inspected and who estimated. Then read the materials line. Steel mesh, aluminum flashing, and replacement wood backed with metal survive. Expanding foam, caulk, plastic vent screen, and a fresh coat of paint do not, and on a wet west side roof they will not last a winter. Third, ask the legal questions out loud. Which species did you identify, and what happens to a captured animal. Release elsewhere in the state requires a permit, so an offer to relocate deserves follow up. Fourth, check whether the quote handles a colony or a single animal, because northern flying squirrels need repeat removals. Last, compare what each company says about insulation, since decontamination is frequently a separate line and it is where two similar looking prices diverge by a lot.
Prevention that fits Washington houses
The single most effective move costs nothing but a saw. Branches within jumping distance of the roof are the highway into your house, and eight feet of clearance ends most of the traffic. Conifer limbs count double, because they give cover as well as access. After that, work the roof edge with a screwdriver in early fall. Press the tip into fascia at the low corners where water sheets off and at the outside ends of soffit runs. Wherever it sinks, replace the board and back the new one with metal rather than nailing a patch over soft wood. Screen gable vents from the inside, and use quarter inch hardware cloth rather than window screen, which a squirrel opens in an afternoon. Finally, remove the reasons to visit. Feeders belong away from the house and off any route to the roof. Birdseed and pet food go into metal containers. None of this evicts an animal already inside, but it keeps a repaired house from becoming interesting again next season.