Astoria is the inverse of Bend. Where the high desert thins its rodents out with a long hard freeze, the north coast almost never freezes at all — the marine layer keeps winter lows in the high 30s, and the population carries through the cold months largely intact. Combine that with 67 inches of annual rain, a hillside packed with century-old wood-frame houses, and a working waterfront built out over the river on pilings, and you get the most continuous rodent pressure of any city we cover. There is no off-season here; there is only a fall sharpening.
Why the roof rat rules here.
The roof rat (Rattus rattus) is a climber, and it favours exactly what Astoria is made of: tall, old, wood-framed Victorians stepped up a steep hill, many with the open vertical wall cavities of balloon-frame construction. A roof rat enters at grade or off an overhanging branch, climbs the wall void, and nests in the attic — often three stories above where the homeowner hears it. The mild wet climate is its native comfort zone. In most of inland Oregon the roof rat is a limited or rare player; in Astoria it is the headline species.
Inland, you set traps where you hear the noise. In an Astoria Victorian, the noise is in the attic and the door is at the foundation — three floors apart, connected by a wall cavity you cannot see into.
The waterfront and the canneries.
Down on the river, it's the Norway rat's (Rattus norvegicus) world. The historic cannery district, the docks, the restaurants and the pier-supported buildings over the water are textbook Norway-rat habitat: burrowable fill, constant food, and a maze of pilings and substructure no exclusion crew can fully close. Riverbank burrows feed a steady supply into adjacent businesses and the homes just uphill of them. Anywhere food service meets old waterfront structure, assume an established Norway-rat baseline rather than a one-off intrusion.
Damp is the real enemy.
Sixty-seven inches of rain does the rodents' work for them. Persistent moisture rots trim, sill plates, fascia and crawl-space framing — and every rotted board is a softened entry point a rat can gnaw or simply push through. A dry-climate house keeps its exclusion seal for years; an Astoria house re-opens itself every wet season as the wood gives way. Effective coastal exclusion is married to moisture control: gutters, grading, crawl-space vapour barriers, and ventilation. Seal a wet house without fixing the water and the seal won't last a winter.
Building stock notes.
Much of Astoria's hillside housing predates 1920 — Uppertown, the Alameda hill streets, Shively-McClure — and carries balloon framing, knob-and-tube-era penetrations, and unscreened foundation and crawl vents. These are roof-rat superhighways. Down by the river (Uniontown, the waterfront, Mill Pond) the issue flips to Norway-rat ingress at grade and under pier structures. Newer construction out toward Warrenton and the Youngs Bay flats is tighter, but sits on low, wet ground where burrowing is easy.
What to do before an operator arrives.
Cut back every tree limb and shrub touching the roofline or walls — on the coast, overhanging vegetation is the single biggest roof-rat assist. Clear leaf litter and standing debris from the foundation. Check the crawl-space access and vents for chew-through and missing screen. And note where you hear activity versus where you find droppings; in a tall coastal house those two points are often on different floors, and the gap between them is the path an operator needs to trace.
