Woodlouse Spider
Stings onlyDysdera crocata · also called sowbug killer, pillbug hunter, orange spider
The woodlouse spider looks alarming — bright orange with oversized fangs — and is one of the more distinctive spiders under a garden stone. The large fangs are for piercing the armoured shells of woodlice, which is essentially its only food.
Quick facts
- Bite risk
- The large fangs can pierce skin and the bite stings sharply for a short time, but it has no lasting effect and is not medically significant.
- Size
- Body 9–15 mm. Body about a thumbnail, with a smooth glossy cream abdomen.
- Appearance
- Unmistakable: a glossy orange-red head, thorax and legs with a smooth, shiny cream or pinkish-grey abdomen, and enormous forward-projecting fangs.
- Web
- No catching web. Builds a silk sleeping cell under stones and logs.
- Found in
- garden, woodpile, basement
- Family
- Dysderidae
- Range
- Most of the United States
How to identify a woodlouse spider
- Glossy orange-red front half and a smooth pale cream abdomen. Nothing else looks like this.
- Very large forward-pointing fangs, visible without magnification.
- Found under stones, logs and pots, usually alongside woodlice.
- Six eyes, like a recluse — but the colour makes confusion unlikely.
How it behaves
Nocturnal hunter of woodlice and pillbugs. Hides under cover during the day.
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.