Large, fast brown spiders appearing in garages, crawl spaces, and basements in late summer and fall are usually giant house spiders. Despite their size and speed they are harmless, but the wandering males and funnel webs make them the top spider complaint on Whidbey Island.
What’s most likely going on
Giant house spiders build funnel webs in undisturbed corners, and the males roam looking for mates in fall — which is when most of the alarming sightings happen. They are essentially harmless and even compete with hobo spiders.
What it means for your home
They rarely bite and pose no real medical risk, so the issue is the startle factor and the webbing. Their presence also points to other insects they are feeding on.
What to do next
We knock down webbing, treat harborage in garages and crawl spaces, and reduce the entry points and prey insects that draw spiders inside. You can read more in our Pest Library entry on giant house spiders, or head straight to our Spider Control service.
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
Are these spiders dangerous?
No — giant house spiders are harmless and rarely bite. Their size and speed are alarming, but they are not a medical threat.
Why so many in fall?
Wandering males searching for mates in late summer and fall account for most indoor sightings.
Not sure what you’re dealing with? Call (360) 206-3293 for a free estimate over the phone, or browse the full Pest Library.
