Giant house spiders are large, fast brown spiders common in Pacific Northwest homes. Despite their intimidating size and speed, they are not dangerous and actually compete with the hobo spider, but they are the most frequent spider complaint on Whidbey Island.
How to identify giant house spiders
Body up to about 3/4 inch with a leg span that can reach 2 to 3 inches, mottled brown with long hairy legs. Males wander in fall looking for mates.
Behavior & season on Whidbey & Fidalgo
They build funnel-shaped webs in undisturbed corners, garages, crawl spaces, and basements. Males roam indoors in late summer and fall, which is when most sightings occur.
Why giant house spiders are a problem
They are essentially harmless — reluctant to bite and not medically significant — but their size, speed, and fall wandering make them alarming, and heavy webbing is a nuisance.
Signs of giant house spiders activity
- Large fast brown spiders indoors, especially in fall
- Funnel webs in corners, garages, and crawl spaces
- Wandering males in living areas at night
- Webbing in undisturbed storage areas
How Salty Dog treats giant house spiders
We knock down webbing, treat harborage in garages and crawl spaces, and seal and reduce the entry points and insect prey that draw spiders inside. Learn more about our Spider Control service, or browse the full Pest Library.
Reviewed by Matthew — Salty Dog Pest Control. WSDA-licensed structural pest applicator (License #101709). Veteran- and family-owned, serving Whidbey Island, Fidalgo Island, and west Skagit County.
Frequently asked questions
Is a giant house spider dangerous?
No. It is harmless and rarely bites, and it competes with the hobo spider — but its size and speed understandably alarm people.
Why do I see them in fall?
Wandering males searching for mates in late summer and fall account for most indoor sightings.
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