Dysdera crocata is a spider species more commonly known as the “woodlouse hunter,” and it is one of the most commonly encountered spider species within homes and buildings throughout the US. The woodlouse hunter is native to Mediterranean Europe, but the species has become prevalent in urban and suburban habitats in Australia, South America, Africa, Asia, and the entirety of the US. Since these spiders live in close association with humans, they often find their way into luggage, shipping cargo, and other items that are shipped around the world.

Many university extension entomologists and insect diagnosticians claim that when it comes to residential pest complaints, the woodlouse hunter is one of the most frequently mentioned indoor spider species. This is due to the species’ habit of invading homes in large numbers, as well as their unique and intimidating appearance that makes them readily distinguishable from other common indoor spider pests.

Woodlouse hunter spiders can be found from Maine to California, and they are particularly prevalent in urban and suburban areas of the northeast. The majority of reported woodlouse hunter sightings occur within homes and buildings. A 2013 study that reviewed reports of woodlouse hunter sightings over a 40 year period found that most occurred in residential homes. According to an online survey of spider sightings, 99 out of 163 woodlouse hunter sightings occurred within homes, many of which are located in Massachusetts.

Adult female woodlouse hunter spiders are around ½ inch in length, while males are slightly smaller, but both sexes can be recognized for having a greyish-white abdomen, as well as a smooth, hairless, and armored reddish-brown exterior. Perhaps most noticeable is this species’ unusually large mouthparts, particularly the fangs. Woodlouse hunters have a strong proclivity to bite, and they will not retreat from humans in response to disturbances, but they will not bite without provocation.

This species’ venom is not dangerous to humans, but their large fangs make bites particularly painful. Because of their oversized fangs, woodlouse hunters are among the few spider species that leave behind visible bite wounds on human skin. Woodlouse hunters are moisture-dependent arachnids that frequently congregate in humid indoor areas like basements, laundry rooms, bathrooms, kitchens and on windowsills.

Have you ever encountered a woodlouse hunter spider?