Adults measure approximately one half of an inch in length. Long-legged and yellow-tan in color, brown recluse spiders of both genders are best distinguished by a fiddle-shaped pattern close to the eyes.
Brown recluse spiders dwell in dark, sheltered places and can be found in homes, barns and basements, as well as outdoor habitats. Webs tend to appear disorganized and are built most commonly near ground level.
Brown recluse spiders are shy and rarely bite unless provoked. They are incapable of biting through clothing and bites sometimes go unnoticed until effects become obvious a few hours later. A pale blister ringed in red appears first. Fever, convulsions, nausea and weakness set in within one day. If untreated, the early blister may become a lesion, resulting in necrosis and severe nerve damage.