The Woodlouse Spider (Dysdera crocata) is a species of arachnid with an international distribution. It is found under logs in warm places, and is often close to woodlice. It also can be found in houses. It spends the day in a silk cocoon and hunts at night without the use of a web. Its diet consists completely of woodlice. Despite the tough exoskeleton of the woodlouse, the spider is able to pierce the body easily with its large fang-like appendages.
The female is 0.43 to 0.60 inches long whilst the male is only 0.37 inches long on average. The thorax is dark-red and the abdomen is yellow. The chelicerae (fang-like appendages) are disproportionately large compared to the body. They have been known to bite humans if handled. The bite can be painful but the venom causes no major medical problems. Localized itching at the bite site is the most common reported symptom.
The courtship is typically aggressive and mates risk injury from each other’s chelicerae. The female lays her eggs in a silk cocoon and is believed to look after her young after hatching.