Giant house spiders are common in Oregon, particularly along the coast and in the western part of the state. These large, fast-moving spiders are not dangerous to people, but their size and speed make them one of the most startling creatures you’ll find indoors. With a leg span reaching about 3 inches, they’re hard to miss when they dart across a floor or wall.
Species and Range in Oregon
The giant house spider found in Oregon is Eratigena atrica, previously classified under the names Tegenaria gigantea and T. duellica. It’s not native to North America. The species originated in Europe and established itself in the Pacific Northwest, where the mild, damp climate closely matches its natural habitat. Its range in the U.S. centers on Washington state and extends into coastal Oregon and parts of British Columbia.
If you live in the Willamette Valley, the Portland metro area, or anywhere along Oregon’s coast, you’re in prime giant house spider territory. They’re less common in the drier, hotter regions east of the Cascades.
How to Identify a Giant House Spider
These spiders are brown to dark brown, with somewhat mottled or banded legs and a slightly paler abdomen marked with faint chevron-shaped patterns. Their most distinctive feature is sheer size: leg spans can reach up to 7.5 centimeters, or roughly 3 inches. The body itself is about the size of a nickel. Males tend to look leggier and thinner than the stockier females.
Giant house spiders build flat, sheet-like funnel webs in corners, behind furniture, and in other undisturbed spots. The web has a funnel-shaped retreat at one end where the spider waits for prey to wander onto the sheet. If you see a messy, flat web tucked into a garage corner with a tubular hiding spot, that’s a strong indicator.
Giant House Spider vs. Hobo Spider
This is the comparison most Oregon residents care about. Hobo spiders (also in the funnel-web family) look similar in color and build similar webs, which creates real confusion. The most reliable visual difference involves the pedipalps, the small arm-like structures near the spider’s mouth. On a male hobo spider, the palps have two prongs, while a giant house spider’s palps have only one. That distinction requires a close look, ideally with a magnifying glass, so it’s not always practical in the moment.
A simpler rule of thumb: size. Giant house spiders are noticeably larger than hobo spiders. If the spider’s leg span is clearly over 2 inches, it’s far more likely to be a giant house spider. The two species also tend to compete, and in areas where giant house spiders are well established, hobo spider populations often decline.
Are They Dangerous?
No. Giant house spiders can technically bite, but they rarely do, and their venom is not medically significant to humans. Spider bites in general cause, at most, mild redness, pain, and swelling. Many go completely unnoticed. The only spiders in North America with venom strong enough to cause serious harm are widow spiders and recluse spiders, neither of which is the giant house spider.
If a giant house spider does bite you, the experience is comparable to a minor bee sting at worst. There’s no tissue damage, no systemic reaction, and no reason for medical concern in otherwise healthy adults. These spiders are also not aggressive. Their first instinct is to run, and they can do so impressively fast, clocking speeds up to half a meter per second. That burst of speed is startling but entirely defensive.
When and Why They Show Up Indoors
The biggest wave of giant house spider sightings in Oregon happens in late summer, typically August and September. This timing leads many people to assume spiders are coming inside to escape cooling temperatures, but that’s a myth. What’s actually happening is mating season. The large spiders you see sprinting across your living room floor are almost always males searching for females. They abandon the safety of their webs and wander openly, which is why they suddenly seem to be everywhere.
Females and juveniles are present in your home year-round, but they stay hidden. They prefer dark, undisturbed spaces like crawlspaces, storage areas, wall voids, and the gaps behind appliances and furniture. Giant house spiders are ideally adapted to indoor life. They don’t wander in from outside when the weather changes. The ones you see inside likely hatched and grew up inside.
Where They Hide in Your Home
Giant house spiders strongly prefer dark, sheltered locations. The most common spots include garages, basements, crawlspaces, closets, and storage rooms that don’t get much foot traffic. Outdoors (or in transitional spaces like sheds), they often settle into stacked firewood or gaps between bricks and stones.
You’re most likely to encounter one in a bathroom or hallway at night, since wandering males are nocturnal. Turning on a light and finding a three-inch spider frozen on the tile is a classic Pacific Northwest experience.
How to Keep Them Out
Because giant house spiders are already indoor residents rather than seasonal invaders, “keeping them out” really means reducing the population already living with you and limiting new entry points.
- Seal gaps and cracks. Check around window frames, door sweeps, foundation vents, and utility pipe entries. Caulk or weatherstrip any openings. This also limits entry by other spider species and insects that serve as prey.
- Reduce clutter. Boxes, stacked storage, and rarely moved items create exactly the kind of dark, undisturbed habitat these spiders prefer. Clearing out basement and garage clutter removes web-building sites.
- Use sticky traps. Commercially available glue-based spider traps are effective for catching wandering males. Place them along walls, in corners, and behind furniture where spiders travel. These traps also give you a useful survey of what species are actually in your home.
- Relocate rather than spray. Indoor control is best limited to mechanical methods. A glass and a piece of cardboard work well for catch-and-release if you prefer not to kill them. Chemical pesticides are generally unnecessary and less effective against spiders than against insects.
- Move firewood away from the house. Stacked wood against an exterior wall is a highway for spiders moving between outdoor and indoor habitats.
Why Some Oregonians Leave Them Alone
Giant house spiders are effective predators of other household pests, including flies, moths, earwigs, and smaller spiders. In areas where giant house spiders thrive, hobo spider numbers tend to drop because the two species compete for the same resources, and the larger giant house spider usually wins. If your concern is hobo spiders specifically, having giant house spiders around works in your favor.
They’re also short-lived as adults. Males typically die shortly after mating season, so the late-summer surge of visible spiders is temporary. By October, the wandering largely stops, and the spiders you do see will be back to hiding in their webs out of sight.