Brown Recluse Spider

The brown recluse spider, Loxosceles reclusa, is a member of the family Sicariidae, native to the central and southern United States. It is best known for the dark violin-shaped marking on the top of its cephalothorax, which has earned it the nickname 'fiddleback spider.'

Unlike many spiders, the brown recluse has only six eyes arranged in three pairs (dyads), rather than the eight eyes found in most spider families, a key feature used in careful identification. It builds an irregular, sparse silk retreat rather than a large orb web, and prefers to remain hidden for most of its life.

The genus Loxosceles includes many related recluse species found in warmer regions of the Americas, Africa, and parts of Europe, but Loxosceles reclusa is the most familiar representative in North America.

• Body: uniformly light to medium brown, with a slightly darker violin- or fiddle-shaped marking on the top of the cephalothorax (the marking can be faint or absent in some individuals).
• Eyes: six eyes arranged in three pairs, unlike the eight eyes of most other spiders—a definitive feature under magnification.
• Legs: long, thin, and uniformly colored without obvious banding or spines.
• Size: body length about 6–12 mm, with legs extending the overall span to roughly the size of a US quarter.
• Lookalikes: many harmless brown spiders are mistaken for recluses; the eye count and lack of banded or spiny legs help distinguish a true recluse.

Brown recluses are found primarily in the central and southern United States, from Texas and Oklahoma east to Georgia and north into parts of the Midwest. They favor dry, dark, undisturbed places—closets, attics, basements, woodpiles, and storage boxes—both indoors and out.

They are active mainly at night and remain hidden in retreats during the day, with activity increasing during the warmer months. In natural settings they can also be found under rocks, bark, and debris.

True to its common name, the brown recluse is a shy, non-aggressive spider that spends most of its time hidden in a silken retreat and avoids open, exposed areas. It is a nocturnal hunter that actively roams at night to capture small insects rather than relying solely on a web to trap prey.

It builds only a small, irregular sheet of silk as a retreat rather than a large capture web. When encountered, its typical response is to flee or remain motionless, and it bites mainly if trapped against skin or clothing.

Brown recluses undergo simple spider development: egg, spiderling through several molts, and adult, without a pupal stage. Females produce silk egg sacs containing dozens of eggs, usually placed within their retreat.

Spiderlings molt multiple times over roughly a year before reaching maturity. Brown recluses are notably long-lived for a spider, with adults capable of surviving one to two years or more, and they can also tolerate extended periods without food.