Wolf Spider
HarmlessTigrosa and Hogna species · also called ground spider, dock spider (misapplied)
The wolf spider is the big, fast, hairy spider that runs across the basement floor, and it is the single most common cause of alarmed spider reports in the United States. It is entirely harmless, it does not build a web, and it hunts by running prey down. Females carry their egg sac attached to the spinnerets and then carry the spiderlings on their back — a behaviour no other US spider shares.
Quick facts
- Bite risk
- Harmless. A bite from a large one can pinch and leave a red mark, in the same category as a bee sting without the venom, but there is no medical significance. Wolf spiders are among the most beneficial predators in a garden.
- Size
- Body 10–35 mm. Body from a thumbnail up to a matchbox in the largest species, with a legspan that can exceed a credit card.
- Appearance
- Robust, hairy and heavily patterned in brown and grey, usually with lengthwise stripes on the head-and-thorax and chevron markings on the abdomen. Two large forward-facing eyes dominate the face.
- Web
- Builds no catching web at all. Some species dig a burrow lined with silk.
- Found in
- garden, grassland, woods, basement, garage, indoors
- Family
- Lycosidae
- Range
- Most of the United States
How to identify a wolf spider
- Two large forward-facing eyes that reflect a torch beam back at you as bright green points. Shine a light across a lawn at night and the wolf spiders light up.
- No web. If it is running on the ground, it is not an orbweaver or a recluse.
- Often carrying a round grey egg sac attached to the rear, or covered in tiny spiderlings.
- Stocky, hairy and clearly patterned — not the uniform plain brown of a recluse.
How it behaves
Chases prey down on foot, mostly at night. Runs from people. Comes indoors in autumn following insects and warmth.
What the wolf spider is confused with
One observation settles each of these.
Recluses are small, plain and unpatterned with thin legs. Wolf spiders are large, hairy and boldly patterned. Size alone usually settles it.
Nursery web spiders carry their egg sac in their jaws, held under the body — wolf spiders drag it behind, attached to the spinnerets.
Fishing spiders are flatter, longer-legged, and have chevron markings with pale-banded legs. They are usually near water.
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.