Brown Recluse Spider Guide

The brown recluse spider is found throughout the south central and midwestern United States. Infestations in these areas are intermittent, becoming more common as one travels westward. Other species of Loxosceles spiders occur in the southwestern U.S. and southern California, but the brown recluse is the most notable and widespread. Recluse spiders are rare outside their native range and are widely over-reported. Occasionally, one or a few spiders may be transported to a non-native area in boxes or furnishings, but infestations seldom become established.

Though variable in size, adult brown recluse spiders with legs extended are about the size of a U.S. quarter. Coloration ranges from tan to dark brown, and the abdomen and legs are uniformly colored with no stripes, bands or mottling. The legs are long and thin and lack conspicuous spines. For laypersons, the most distinguishing feature of a brown recluse is a dark violin-shaped mark on its back, with the neck of the violin pointing toward the rear (abdomen) of the spider. This feature is consistent in adult brown recluses, but sometimes less obvious in younger spiders.

In nature, brown recluse spiders live outdoors under rocks, logs, woodpiles and debris. The spider is also well adapted to living indoors with humans. They are resilient enough to withstand winters in unheated basements and stifling summer temperatures in attics, persisting many months without food or water. The brown recluse hunts at night seeking insect prey, either alive or dead. It does not employ a web to capture food — webs strung along walls, ceilings, outdoor vegetation, and in other exposed areas are nearly always associated with other types of spiders.