Brown Recluse Spiders: Identification, Bites and Real Range
The brown recluse (Loxosceles reclusa) is a small, plain brown spider of the south-central United States whose bite can, occasionally, kill skin around the wound. It is about 7 to 12 mm long in the body (roughly 3/8 of an inch), with six eyes in three pairs, uniformly coloured legs with no spines or bands, and an unpatterned abdomen. It is not aggressive: most bites happen when a spider is pressed against skin in bedding or clothing, and most heal without lasting damage. Outside its range, sightings and “bites” are almost always something else.
Inside its range the brown recluse can be a common house spider, sometimes in the hundreds. Outside it, a brown spider in the house is very unlikely to be one. Our count of iNaturalist records shows how sharp that boundary is.
The spider in brief
The brown recluse is one of eleven native US recluse spiders (genus Loxosceles), and the only one properly called the brown recluse (UC Statewide IPM Program). It is also called the violin or fiddleback spider, for the dark violin-shaped patch on the front body section. It hides by day in dark, dry, undisturbed places and hunts small insects, alive or dead, at night. It does well around people: UC IPM cites 44 caught on sticky traps in a Tennessee home in one day.
Identification: the five checks
Most guides lead with the violin, but UC IPM says the marking “is not always distinct, so it should not be used as an identifying character.” A spider must show all five features below to be a recluse; failing any one rules it out. Our spider identification guide explains the order in which to check them.
| Feature | Brown recluse | Wolf spider | Southern house spider (male) | Cellar spider |
|---|---|---|---|---|
| Eyes | 6, in three pairs in a semicircle | 8: four small in a row, two large, two on top | 8, clumped together | 8 |
| Legs | One colour, fine hairs only, no spines | Hairy, often banded, with spines | Long, slender, with black spines | Extremely long and thin |
| Abdomen | One colour, cream to dark brown | Patterned | Khaki to amber | Pale, often with markings |
| Body length | 7 to 12 mm (about 3/8 in) | 16 to 35 mm in common large species | 9 to 10 mm | 6 to 8 mm |
| Web | Small, messy retreat silk hidden behind objects | No catching web; hunts on the ground | Flat, tangled web around a crevice | Loose, untidy web in corners |
| Where you see it | Boxes, closets, shoes, basements, at night | Floors, garages, after autumn rain | Crevices in masonry and dark corners of buildings, across the South | Basements and room corners |
Compiled by The Pest Control Brief from UC IPM Pest Notes 7468 and 7442, UC Riverside Spider Research, UF/IFAS EENY-144, Penn State Extension and LSU AgCenter.
The definitive check is six equal-sized eyes in three pairs (dyads) with gaps between them, visible with a hand lens; almost every other spider has eight. UC Riverside’s spider lab adds that more than one colour on the legs, more than one pigment on the abdomen, or thick leg spines all rule out a recluse.
How big is a brown recluse?
Smaller than most people expect. LSU AgCenter gives females 8 to 12 mm and males 7 to 9 mm of body length; with legs, the Missouri Department of Conservation puts it at about an inch. UC Riverside’s rule: a body longer than half an inch is not a recluse.
Brown recluse vs wolf spider
Size settles it fast: Penn State gives Carolina wolf spider females 22 to 35 mm of body length, about three times a recluse. Wolf spiders hunt in the open, have patterned bodies and spiny legs, and their eyes reflect green in a torch beam. They are harmless; see our wolf spider guide. Timing helps too: recluse sightings peak in June and July, wolf spiders in October, when wandering males come indoors.
The index removes the effect of more people recording in summer. In raw numbers the peak is sharper: 1,438 brown recluse records in July against 173 in January, and 7,453 of 8,684 (86 per cent) between April and October. UC Riverside tells physicians that most recluse bites occur from April to September and that even in heated homes recluses largely disappear for the winter. A 2012 clinical series found the same pattern, with 43 of 45 suspected bites (95.6 per cent) between April and October.
Where do brown recluse spiders live?
The native range runs from south-eastern Nebraska to south-western Ohio and south through Texas to north Georgia (UC IPM). Penn State Extension lists 16 states with established populations: Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Ohio, Oklahoma, Tennessee and Texas. It is patchy even there: LSU says it is common in northern Louisiana and exceedingly uncommon in the south of the state.
Our state count shows how hard the boundary is. Of 8,669 research-grade brown recluse records with a US state, 8,601 (99.2 per cent) come from those 16 states. Kansas, Missouri and Oklahoma lead, each with 15 to 20 records per 10,000 observations of anything. California, Arizona, Florida, Pennsylvania, New York and Washington together have one record.
Spiders do travel in boxes and furniture, which is why Penn State notes isolated finds in states such as California and Pennsylvania. UC IPM says fewer than 20 verified specimens have been found in California in several decades, and searches nearby found no others. A stowaway is not a population.
Why are there brown recluse spiders in my house?
Inside the range, because a house is good recluse habitat: dry, dark, undisturbed and full of small insects. Outdoors they live under rocks, logs and bark; around people they use boxes, stored clothing, wall voids, attics and basements. Kentucky notes they survive unheated basements and hot attics, “persisting many months without food or water,” so a house that has them usually has several.
Webs, shed skins and life cycle
Recluses make only small, messy retreat silk in hiding places. Kentucky says webs on walls, ceilings or plants are “almost always associated with other types of spiders.” A better sign is the shed skin: recluses moult five to eight times, and the cast skins have a splayed, outstretched look that helps confirm an infestation.
Penn State says females mate in June or July and lay twenty to fifty eggs per sac, two to five sacs in a lifetime. UF/IFAS gives about 336 days from egg to adult, and UC IPM an average lifespan of 2 to 4 years, with some living more than 7 years in the laboratory. See our guide to how long spiders live.
Venom and how bites usually go
The venom can cause skin necrosis, but the fangs are small, the spider cannot bite through clothing (Kentucky), and CDC notes it cannot bite without counterpressure, such as being trapped against skin. Penn State Extension estimates that about 90 per cent of brown recluse bites cause no reaction or a small red bump of about 5 mm that heals on its own, about 10 per cent cause dermonecrotic lesions, and fewer than 1 per cent cause systemic illness. Two clinical series from inside the range give a similar picture.
Both studies counted suspected bites, mostly diagnosed on appearance: in the Vanderbilt series only 13 of 111 patients brought the spider in. They describe what doctors in recluse country see, not verified envenomations.
Are brown recluse spiders deadly?
Very rarely. UC IPM says deaths have been reported in children but are extremely rare. Penn State notes that systemic reactions, including destruction of red blood cells and kidney injury, are most common in children and are a medical emergency. Neither clinical series recorded a death.
Brown recluse bite stages and symptoms
This describes the usual course reported by extension and medical sources; it is not a way to diagnose a wound. A doctor should see any bite that is spreading, darkening, blistering or comes with fever, and CDC advises professional care for a necrotic lesion. Read more about why marks are weak evidence in our bite identification guide.
| Time after the bite | What is typically reported | Source |
|---|---|---|
| At the bite | Usually painless or a mild sting; many people do not notice it | University of Kentucky; CDC |
| 3 to 8 hours | Redness, swelling and tenderness at the site; a small white blister may form | University of Kentucky; CDC |
| First 3 weeks | Most bites stay local and heal within 3 weeks | University of Kentucky |
| Days 7 to 14 | In the minority that progress, the centre turns dry, sunken and bluish or purple, then ulcerates | UC Riverside; Kentucky |
| 2 to 4 months | Necrotic wounds heal slowly; most recluse bites are healed by the third month; some scar | Penn State; UC Riverside |
Compiled by The Pest Control Brief from the University of Kentucky (ENTFACT-631), CDC NIOSH, Penn State Extension and Stoecker, Vetter and Dyer, JAMA Dermatology 2017.
Signs that point away from a recluse
A checklist published by UC Riverside’s Rick Vetter and two dermatologists, NOT RECLUSE, lists features that make a recluse bite unlikely: several lesions at once; a lesion that appeared after gardening; one appearing from October to March; a red centre; a lesion raised more than 1 cm above the skin; a sore oozing pus; one larger than 10 cm; and ulceration before day 7. UC IPM adds that in one study at 11 university medical centres, 29 per cent of patients who came in for a “spider bite” had MRSA. If you have the spider, bring it: Kentucky says even crushed specimens can usually be identified.
Outside the range the odds are lopsided. South Carolina physicians diagnosed 738 recluse bites in 2004 in a state with 44 verified specimens since 1953, a mismatch covered in our article on whether spiders bite in your sleep.
The Kansas house
The best evidence on real-world risk comes from a 19th-century home in Lenexa, Kansas. Over six months in 2001, the family collected 2,055 brown recluses, at least 400 of them large enough to bite, and none of the four residents was bitten (Vetter and Barger, Journal of Medical Entomology, 2002). UC IPM adds that in nearly a decade there, only one bite was ever suspected, and it healed.
How to get rid of brown recluse spiders in your house
Confirm the identification first. Kentucky’s guidance is that infestations are hard to eradicate and treatment is best done by professionals, because the spiders hide where sprays cannot reach.
- Survey with flat glue traps. Kentucky recommends dozens of flat sticky cards, without a raised rim, in corners and along wall and floor junctions, especially behind furniture and clutter. A 2013 Journal of Insect Science trial found brown recluses preferred an uncovered flat trap; covered traps are safer around children and pets. Counts show whether the problem is shrinking.
- Cut the clutter. Move stored items into sealed plastic bins, clear cardboard from basements and garages, and wear gloves and long sleeves when sorting boxes.
- Break the routes to people. Pull beds away from walls, remove bed skirts and anything stored under the bed, keep shoes and clothes off the floor and shake them out before wearing.
- Seal and clear outside. Close gaps under doors, around vents and utility lines and under siding, and move firewood and debris away from the foundation. See our guide to pest-proofing your home.
- Targeted crack and crevice treatment. Kentucky notes that elimination often needs insecticide placed into hiding places, along with dusts in voids and attics. Follow the label exactly. Total-release foggers are seldom effective against recluses.
One or two recluses in a house inside the range is normal and, LSU says, no cause for alarm. Repeated catches on traps, spiders in bedrooms or a household with young children are reasons to call a licensed professional. See our guide to getting rid of spiders in the house and spider control costs.
Frequently asked questions
Are brown recluse spiders poisonous?
They are venomous, not poisonous: the venom is injected by a bite. Most bites cause little or nothing. Penn State estimates about 90 per cent heal on their own, around 10 per cent cause a necrotic skin wound that takes two to four months to heal, and under 1 per cent cause systemic illness, which is most serious in children. Anyone with a worsening bite should see a doctor.
What is a brown recluse?
A small brown spider, Loxosceles reclusa, native to the south-central United States from Nebraska and Ohio south to Texas and Georgia. It has six eyes in three pairs, a dark violin-shaped mark on the front body section, uniformly coloured legs and abdomen, and a body about 7 to 12 mm long. It hides by day and hunts insects at night.
How to get rid of brown recluse spiders in your house?
Confirm the identification, then combine flat glue traps along walls and behind furniture, clutter reduction with sealed plastic storage, beds pulled away from walls and sealing of exterior gaps. University of Kentucky entomologists advise that established infestations usually also need targeted crack and crevice treatment, best done by a licensed professional. Foggers are seldom effective.
Do brown recluse spiders make webs?
Only small, irregular retreat webs hidden behind or under objects, which they also use for egg sacs. They do not build catching webs out in the open. Webs on walls, ceilings, windows or plants almost always belong to other spiders, usually harmless cobweb or cellar spiders, according to the University of Kentucky.
What do brown recluse spiders look like?
Tan to dark brown, with a body about 3/8 of an inch long and legs that make it roughly the size of a US quarter. The legs are one colour with fine hairs and no spines or bands, the abdomen is a single colour, and there are six eyes in three pairs. The violin mark is often present but is the least reliable feature, so check the eyes.
Sources
- UC Statewide IPM Program. Pest Notes: Brown Recluse and Other Recluse Spiders, Publication 7468 (R. S. Vetter).
- UC Statewide IPM Program. Pest Notes: Spiders, Publication 7442.
- UC Riverside Spider Research (R. S. Vetter). How to identify (and misidentify) a brown recluse spider; What is NOT a recluse bite; The myth of the brown recluse.
- University of Kentucky Entomology. ENTFACT-631: Brown Recluse Spider (M. F. Potter), revised 2026.
- Penn State Extension. Brown Recluse Spiders; Wolf Spiders; Longbodied Cellar Spider.
- LSU AgCenter. Loxosceles spp., Brown Recluse and Mediterranean Recluse Spiders.
- UF/IFAS Featured Creatures. EENY-233, Brown Recluse Spider (Weems and Whitcomb, archival 2002); EENY-144, Southern House Spider (Edwards and McCanless).
- Missouri Department of Conservation. Brown Recluse (Violin Spider) field guide.
- CDC NIOSH. Venomous Spiders.
- Vetter R. S., Barger D. K. An infestation of 2,055 brown recluse spiders and no envenomations in a Kansas home. Journal of Medical Entomology 39(6): 948 to 951, 2002.
- Vetter R. S. Seasonality of brown recluse spiders submitted by the general public. Toxicon 58: 623 to 625, 2011; Rader R. K. et al. Seasonality of brown recluse populations is reflected by numbers of brown recluse envenomations. Toxicon 60: 1 to 3, 2012.
- Cacy J., Mold J. W. The clinical characteristics of brown recluse spider bites treated by family physicians. Journal of Family Practice 48(7): 536 to 542, 1999.
- Wright S. W. et al. Clinical presentation and outcome of brown recluse spider bite. Annals of Emergency Medicine 30(1): 28 to 32, 1997.
- Stoecker W. V., Vetter R. S., Dyer J. A. NOT RECLUSE: a mnemonic device to avoid false diagnosis of brown recluse spider bites. JAMA Dermatology 153: 377 to 378, 2017.
- Frithsen I. L., Vetter R. S., Stocks I. C. Reports of envenomation by brown recluse spiders exceed verified specimens of Loxosceles spiders in South Carolina. Journal of the American Board of Family Medicine 20(5): 483 to 488, 2007.
- Parks J., Stoecker W. V., Paige R. L. Trap design for the brown recluse spider, Loxosceles reclusa. Journal of Insect Science 13: 57, 2013.
- The Pest Control Brief analysis of iNaturalist research-grade records, pulled October 2026.
