This is one of the few species in the UK that can bite humans. Although their venom is not dangerous to us, their bite can be painful due to the strength of their jaws and some people may have an allergic reaction to the venom. However, they are unlikely to bite.
Female woodlouse spiders are 11-15mm and males are 9-10mm. They have a dark red thorax and legs, and their abdomen is a creamy yellow-brown. The most distinguishing characteristic of this spider is its enormous jaws.
They are fairly common across Britain, but they are locally distributed. They are a European species but have been introduced to North America.
Woodlouse spiders are found under logs in warm places usually in the vicinity of woodlice. They are occasionally found in houses.
They feed almost exclusively on woodlice. Woodlice have an armoured body that is too tough for most spiders to crack, but the jaws of the woodlouse spider are strong enough to break through.
They are nocturnal hunters that don't build a web. During the day, they rest in a silken cell.
Courtship of these spiders is often very aggressive. The male and the female have to be careful not to get injured by the other's jaws. The female lays her eggs in the same silk retreat that she stays in during the day. It is thought that after hatching the female takes care of her young.
This spider is not protected by law in the UK.