What Does a Brown Recluse Look Like?

The brown recluse spider is found only in certain areas of the country. If they are located in your region, it's important to know what they look like. It's rare for them to bite people, but when they do, their venom can cause serious wounds.

On average, these spiders are about the size of a quarter, including their legs. They are tan to dark brown and have a few distinct characteristics. These include 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. An expert examination can rule out other species that look like a brown recluse but aren't as potentially dangerous.

This article discusses why brown recluse spiders are dangerous and how to identify them.

Why Brown Recluse Spiders Are Dangerous

Though bites from a brown recluse are rare, they can be dangerous. These spiders are not aggressive. However, they may bite if you accidentally roll over on one or if it's 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. There's no blood test or culture that can detect 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 people with compromised immune systems, the elderly, and children.

If you think you've been bitten by a brown recluse, apply ice to the affected area, elevate it, and seek medical attention immediately. 

Recap

The venom from a brown recluse can cause serious symptoms, especially in the elderly, children, or those with compromised immune systems. If you think you may have been bitten by a brown recluse, get medical help immediately.

Brown Recluse Spider Bite Symptoms

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

In more serious cases, a wound or lesion may form. It could have 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. It can eventually become a necrotic ulcer, which has dead tissues and leaves a deep scar.

Rarely, bites produce a systemic reaction (throughout the body) accompanied by fever, chills, dizziness, rash, or vomiting.

Recap

Most brown recluse bites can heal in a few weeks. Some can be severe and destroy skin tissue, causing a serious wound. In rare cases, it can cause fevers, rash, dizziness, and vomiting.

How to Rule Out the Brown Recluse

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.

Still, 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. 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 a related species.

Rick Vetter

Look at Its Legs

When identifying a spider, you may be able to figure out if it is a brown recluse from its anatomy.

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

The next way to identify a brown recluse is to look at the spider's eyes.

Loxosceles
Pablo Dolsan / Getty Images

Brown recluse spiders have six eyes. The eyes are 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. However, if the eyes aren't in the proper pattern, then it's definitely not a brown recluse.

Recap

Brown recluse spiders have slanted legs that come up to a point with a body that sits low. They have six eyes, arranged in three groups of two each.

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 long. 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

Recap

A brown recluse is about the size of a quarter when you include both its body and legs. It usually has a violin-shaped mark on its back, but that may be found on other spiders as well.

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.

To avoid an infestation of brown recluse spiders, 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

Summary

While brown recluse bites are rare, they can be dangerous. Brown recluse spiders are found in the south central part of the United States. They can be identified by slanted legs, six eyes, and a violin-shaped mark on their back.

While most bites heal without complications, some people can have severe reactions, including a serious wound, fever, dizziness, rash, or vomiting. Seek medical care immediately if you think you've been bitten by a brown recluse.

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 given within a few hours of being bitten.

  • 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 whether it is actually a brown recluse or another type of spider.

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3 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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