Crevice Spider

Category:

Actual Size: 13 mm to 19 mm

Characteristics: Males are brown or amber. Females are black, or charcoal and look like small tarantulas.

Legs: 8

Habitat: Constructs webs at higher elevations around cracks and crevices on the exterior of homes, barns, and other structures. Will also spin webs in outdoor vegetation.

Habits:

  • Sometimes referred to as the southern house spider.
  • Looks similar to the brown recluse, but their venom is not toxic.
  • Has an unnerving tendency to crawl across anything in their path, including human skin.

Crevice Spiders in Northern Utah

Crevice spiders sometimes referred to as southern house spiders, are commonly found in Northern Utah. They are frequently mistaken for brown recluse spiders, however, males have eight eyes squeezed together, and females are velvety black and look more like small tarantulas. Yet both sexes are frequently mistaken for recluses. These spiders make a cottony web on a flat surface where they hide in a hole, waiting for prey. Although they aren’t toxic, crevice spiders have an unnerving tendency to crawl across anything in their path, including human skin.

Crevice Spider Habitat

The crevice spider is partial to spaces within the masonry of buildings; especially dark recesses of window sills, shutters, and overhangs. Females and juveniles make specialized webs that are occasionally found under tree bark but are frequently seen on houses, barns, bridges, and other man-made structures. Crevice spiders will build webs in high places, and typically in the cracks and crevices of homes, garages, and sheds. These spiders will also spin their webs outside, in plants, cactus, and vegetation. The webs of the crevice spider are flat and tangled, having a woolly texture.

Crevice Spider Behaviors, Threats or Dangers

While they look similar to the dangerous recluse spider species, crevice spiders are harmless to humans. They are reluctant to bite, and their venom is not medically significant. Male crevice spiders sometimes appear aggressive, but they do not bite unless trapped and their mouthparts are too small to easily penetrate human skin. The crevice spider can be a particular pest during the winter, building up populations in unkept areas of houses, outbuildings, warehouses, and similar structures in addition to outdoor habitats.

If you are dealing with excess crevice spiders, contact your local spider exterminators.