The Dysderidae, also known as woodlouse hunters, sowbug-eating spiders, and cell spiders, are a family of araneomorph spiders first described by Carl Ludwig Koch in 1837. They are found primarily in Eurasia, extending into North Africa with very few species occurring in South America. Dysdera crocata is introduced into many regions of the world.

Dysderids generally have six eyes, and are haplogyne, i.e. the females lack a sclerotized epigyne. There is a substantial number of genera, but two of them, Dysdera and Harpactea, account for a very large number of the species and are widespread across the family's range. One species, Dysdera crocata (the woodlouse hunter), has been transported over much of the planet together with its preferred foods—woodlice. Dysdera also feeds on beetles. These spiders have very large chelicerae, which they use to pierce the armored bodies of woodlice and beetles. There are also some reports that they have a mildly toxic venom that can cause local reactions in humans.

The spiders have their six eyes arranged in a semicircle like segestrids, but have only the first two pairs of legs produced forward. Dysdera crocata has a characteristic coloring, which can only be confused with spiders in the trachelid genera Trachelas and Meriola: the carapace is dull red-brown and the abdomen gray or tan.