The brown recluse spider, Loxosceles reclusa, is recognized for its venom, which contributes to public concern. This spider is shy and reclusive. Despite its reputation, bites are uncommon, typically occurring only when the spider feels threatened or is inadvertently pressed against the skin.
Understanding Brown Recluse Reactions to Threat
Brown recluse spiders do not typically exhibit thanatosis, commonly known as “playing dead.” Instead, their primary defensive behaviors involve freezing, remaining motionless, or rapidly fleeing from perceived danger. This stillness, or tonic immobility, can sometimes be mistaken for feigning death. They are generally not aggressive and prefer to avoid confrontation.
Bites from brown recluse spiders almost always result from accidental contact. This often happens when the spider becomes trapped against a person’s skin, such as when putting on clothing or shoes that have been left undisturbed. Bites can also occur if someone rolls onto a spider in bed or disturbs stored items where the spider has sought refuge. These spiders are nocturnal, retreating to dark, secluded areas during daylight hours.
Recognizing a Brown Recluse
Identifying a brown recluse spider involves looking for specific characteristics, as misidentification is common. A distinctive “violin” or “fiddle” shape is present on its cephalothorax, the fused head and thorax where the legs attach. The “neck” of this violin marking points toward the spider’s abdomen.
Another key identification feature is their unique eye arrangement: unlike most spiders that have eight eyes, brown recluses possess six eyes arranged in three pairs in a semicircle. The spider’s coloration is uniformly brown, without any stripes, bands, or patterns on its legs or abdomen. Their bodies have fine hairs, appearing relatively hairless, and their legs are slender, lacking coarse spines. Adult brown recluses measure between 6 to 20 millimeters (0.24 to 0.79 inches) in body length, with a leg span of about 2.5 centimeters (1 inch), roughly the size of a quarter. To ensure accurate identification, observe all these characteristics together, as no single feature is definitive on its own.
Coexisting Safely with Brown Recluse Spiders
To reduce encounters with brown recluse spiders, minimize clutter in storage areas such as attics, basements, closets, and garages. Sealing cracks and crevices in home foundations, around doors, vents, and eaves can limit their entry. Before wearing shoes or clothing that have been stored, or using towels and bedding, shake them out thoroughly. Exercising caution when reaching into dark, undisturbed spaces, like woodpiles or boxes, is advisable.
If a brown recluse spider is discovered, avoid provoking it. Safe removal can be achieved by carefully corralling the spider into a container without direct contact. Symptoms of a brown recluse bite can vary, with many resulting in minor reactions. The initial bite is often painless, but localized pain, itching, and redness typically develop within two to eight hours. More severe bites may lead to a necrotizing ulcer, which is tissue death, appearing 12 to 36 hours to several days after the bite. These ulcers can take months to heal and may leave scarring. Systemic symptoms, including fever, chills, nausea, and muscle or joint pain, can also occur, particularly in children. Seek medical attention if a brown recluse bite is suspected, or if severe symptoms or signs of infection develop.