Giant House Spider
HarmlessEratigena duellica · also called European house spider
The giant house spider is the large, fast, long-legged spider that appears in Pacific Northwest homes in autumn, usually running across a carpet at speed or sitting in a bathtub it cannot climb out of. It is harmless, and it competes with and eats hobo spiders.
Quick facts
- Bite risk
- Harmless. Reluctant to bite and unable to do meaningful harm. Its presence actively reduces hobo spider numbers.
- Size
- Body 12–20 mm. One of the biggest spiders found indoors in the north — legspan can approach the size of your palm.
- Appearance
- Large, long-legged and brown with a mottled abdomen and clearly banded legs. Males, which are the ones seen running across floors, have very long legs relative to a modest body.
- Web
- Large flat sheet web with a funnel retreat, in garages, sheds, basements and behind furniture.
- Found in
- indoors, basement, garage
- Family
- Agelenidae
- Range
- 6 US states
How to identify a giant house spider
- Large size with a legspan often over two inches.
- Clearly banded legs — the fastest way to separate it from a hobo spider.
- Funnel-shaped sheet web in a garage or basement corner.
- Autumn wandering males are the usual encounter.
How it behaves
Sits in its funnel most of the year. Males wander in search of females in late summer and autumn, which is when almost all sightings happen.
What the giant house spider is confused with
One observation settles each of these.
Check the legs: banded means giant house spider, plain means hobo.
Wolf spiders build no web and have two large forward-facing eyes that shine in torchlight.
Where it lives
If you think you were bitten
- Most suspected spider bites are not spider bites. Studies of patients presenting with a “spider bite” repeatedly find that the large majority are bacterial skin infections — frequently MRSA — which need antibiotics rather than reassurance. A spreading, painful, pus-filled sore is far more likely to be an infection than a spider.
- Wash it, ice it, and watch it. Clean the area with soap and water, apply a cold pack, and keep an eye on it.
- Get medical care if the wound spreads or darkens, if you develop cramping, sweating, fever or severe abdominal pain, or if you are confident it was a widow or a recluse.
- Bring the spider only if it is already dead and to hand. Do not go looking for it. Doctors treat symptoms, not species.
In the US, the Poison Help line is 1-800-222-1222. This site is a reference, not medical advice.