What Does a Brown Recluse Look Like?

The brown recluse spider is found only in certain areas of the country, and it is rare for them to bite people. If you are in this region of the country, however, you will want to know what a brown recluse spider looks like, as their venom is capable of causing serious wounds.

These spiders are, on average, about the size of a quarter, including their legs. They are tan to dark brown and have a few distinct characteristics, including six eyes (most spiders have eight), and a violin- or fiddle-shaped marking.

Unfortunately, these descriptions don’t always hold up and you need an expert to accurately identify a brown recluse spider. It takes a close examination of the spider itself to rule out all the other species that look like a brown recluse but aren't as potentially dangerous.

If anything, identifying a brown recluse is more about ruling out what it isn't rather than figuring out what it is.

Why Brown Recluse Spiders Are Dangerous

Though bites from a brown recluse are rare, they can be dangerous. These spiders are not aggressive, but may bite if you inadvertently roll over on one in your bed, for example, or if one has been hiding in a piece of clothing.

Furthermore, a bite can be mistaken for something minor, like a red bump or a small wound. There is nothing that clearly identifies the bite of a brown recluse, and there is no blood test or culture that can show the presence of brown recluse venom in a suspected spider bite.

The venom of the brown recluse can cause a mild reaction or a severe one. Severe reactions are more common in immunocompromised people, the elderly, and children. If you suspect you have been bitten by a brown recluse spider, apply ice, elevate the affected area, and seek medical attention immediately. 

Brown Recluse Spider Bite Symptoms

A brown recluse bite is usually painless, and symptoms may not appear for several hours, at which point the area might become red, swollen, and tender. The majority of bites remain localized and heal within a few weeks without serious complications or medical treatment.

In more serious cases, a lesion may form, appearing as a dry, sinking bluish patch with irregular edges, a pale center, and redness on the outside. As the venom continues to destroy tissue, the bite wound may expand up to several inches over a period of days or weeks, eventually becoming a necrotic ulcer that can leave a deep scar.

Rarely, bites produce a systemic reaction accompanied by fever, chills, dizziness, rash, or vomiting.

How to Rule Out the Brown Recluse

If you've been bitten by a spider that you think may be a brown recluse, the best thing to do is to try to rule out that possibility by following these steps.

Determine If They Live in Your Area

Brown recluse spiders live in a well-defined area in the South Central part of the United States. They are called "recluse" because they are hard to find even in the regions in which they reside.

The scientific name for the brown recluse is Loxosceles reclusa, and they live in the red-colored area of the map below. The other colored areas on the map are home to other Loxosceles species (such as the Texan recluse, desert recluse, and more). These are related to the brown recluse and all have similar venom. Indeed, some of the other Loxesceles species have more dangerous venom than the brown recluse.

If the spider was found outside the known habitat of a brown recluse, then it is almost certainly not this type of spider. If it is outside of the other areas, it's not even related to the brown recluse.

Brown recluse distribution map

Rick Vetter

Brown recluse spiders like dark, dingy places where they can hide under things. Within their habitat, there can be serious infestations. Hence, if there is one spider, there are most likely dozens or even hundreds. However, even in homes with extensive infestations, it is unusual to be bitten.

If you have a specimen from inside the brown recluse zone (or if you think the experts are wrong about your particular spider even though you aren't in brown recluse territory) you can try to figure out if it is a brown recluse from its anatomy.

Look at Its Legs

Loxosceles actually means "slanted legs." If you look at a brown recluse from the side, you can see how the body sits low and the legs angle up to a point. It's that angular, slanted leg shape that gives the brown recluse its scientific name.

Loxosceles recluse spider capture in a plastic cup
Joao Paulo Burini / Getty Images

Two more distinct features of brown recluse legs include:

  • No spines: Unlike many other spider species, Loxosceles does not have spikes or spines on its legs. They are smooth.
  • Solid color: Some spiders have multicolored legs, but Loxosceles legs are solid, with no stripes and no patterns.

If a spider doesn't have this type of leg, it's definitely not a brown recluse. If it does, you'll want to look at some other characteristics.

Check for Three Groups of Two Eyes

Assuming you're in brown recluse country and you have a spider with a low-slung body on angled, smooth, solid color legs, the next thing is to look at the spider's eyes.

Loxosceles
Pablo Dolsan / Getty Images

Brown recluse spiders have six eyes. They're paired in what are known as diads (groups of two) and arranged on the front and sides of the spider's head. Other spider species might have eight eyes, or six eyes arranged in two triads (groups of three). You can't be sure it is a brown recluse based only on the eyes, but if the eyes aren't in the proper pattern, then it's definitely not a brown recluse.

Inspect Its Body

There are two more characteristics necessary for this to be a Loxosceles:

Brown recluse (Loxosceles) spider on a ruler
Joao Paulo Burini / Getty Images
  • The body (without legs) has to be no more than 3/8 of an inch. Including the legs, the average brown recluse is around the size of a quarter.
  • The abdomen (big round part on the backside) needs to be a little fuzzy with very fine hairs and a solid color.

Find the Fiddle Marking

The one feature most commonly noted in descriptions of the brown recluse is the violin-shaped mark on its back.

Not all brown recluses have the classic violin mark. Even if it's there, you might not be able to clearly see it. Furthermore, there are spiders that also have the violin marking on their backs that are not brown recluses.

Desert recluse spider close up
The classic violin mark isn't obvious on all species of loxosceles like this desert recluse, but the venom is just as bad.

Marshal Hedin

How to Avoid an Infestation

Brown recluse spiders are difficult to get rid of, largely because of their tendency to hide in dark areas. Crevices, corners, and wall-floor junctures, especially behind clutter and storage areas, make for ideal hiding places.

The best way to avoid an infestation of brown recluse spiders is to seal up the places in your home where they are likely to enter. Strategies include:

  • Using weather-stripping around windows and window frames
  • Filling cracks in floorboards with plastic wood filler or wood adhesive
  • Removing clutter

Frequently Asked Questions

How do you get rid of brown recluse spiders?

Glue traps can catch the spiders, but it's best to call a professional exterminator who can use appropriate pesticides, which are more effective.

How do you treat a brown recluse bite?

Antihistamines, colchicine, dapsone, and corticosteroids are medications used to relieve symptoms. Antivenom, consisting of antibodies that neutralize the venom, can prevent large skin ulcers if administered within a few hours.

What should you do if you find a brown recluse in your home?

Call an exterminator. If you think you have been bitten by a brown recluse spider, apply ice, elevate the affected area, and seek medical attention immediately. Try to capture the spider so an expert can determine if it is actually a brown recluse, or another type of spider.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. University of Kentucky. Entomology. Brown recluse spider.

  2. Illinois Department of Public Health. Brown recluse and black widow spiders.

  3. Rahmani F, Banan Khojasteh SM, Ebrahimi Bakhtavar H, et al. Poisonous spiders: Bites, symptoms, and treatment; An educational reviewEmerg (Tehran). 2014;2(2):54-58.

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