The name “brown recluse” conjures up nightmarish visuals for a majority of the population, and not only for those who have arachnophobia. This unique spider is found in 16 states , most of which are in the country’s southern half. However, this doesn’t mean they can’t be found elsewhere and are sometimes unintentionally transported to non-native states, which means there’s potential for you to run into at least one during your lifetime. And look out if you have to deal with a brown recluse infestation .

While these venomous spiders get a bad reputation, there are steps you can take if you happen to be bitten — some may even save your life.

Where Brown Recluse Spiders Can Be Found

The brown recluse is ectothermic, meaning it relies solely on an external heat source for warmth, hence why the species prefers warm-weather locations over colder climates. Knowing this fact is two-fold: Their preference for warmer temperatures may lead them to migrate indoors during cooler months. While these spiders are typically reclusive (hence the name) and avoid human interaction, it’s not uncommon to spot them in your house. This is why bite prevention and treatment are crucial if you live in these states.

Likely Places To Find A Brown Recluse Indoors

Their name gives nod to their preference to hide away versus chancing a human or predator encounter, but it doesn’t always mean that human-spider interactions are avoidable. During cooler months, those living in known brown recluse states may find themselves face-to-face with the spider in places such as undisturbed environments, storage areas, closets, cubbies, cabinets, and under furniture, according to Jeremy Bradley, a training manager at Arrow Exterminators .

“For a natural approach, general good housekeeping and lawn maintenance practices will help prevent brown recluses,” Bradley shares. “Reduce available sources of food, water, and shelter. Brown recluses are attracted to the presence of insects and arthropods, which they hunt and eat.”

Eliminating their food source (i.e. smaller pests) and locating entry points such as small openings, cracks and crevices, woodpiles, boxes, tires, and similar yard items will also help. Sealing cracks around electrical wires and plumbing is also helpful in preventing spider entry points.

Bradley also adds that the gender of a brown recluse also makes a difference. “Interestingly, female brown recluses mate just once to produce eggs throughout their lifetime, and they can produce several egg sacs each year. This means just one female can establish an infestation. Inspect items before bringing them to new locations to ensure you don’t accidentally introduce a brown recluse — or egg sac — to your home.”

How To Identify A Brown Recluse If You’re Bitten

Two other indicators of a spider being a brown recluse will be its habitual hunting pattern. The brown recluse is active mainly at night, spending its days out of sight in its web. Additionally, a brown recluse will not make its home out in the open. Therefore, it’s not likely a brown recluse is responsible if a web is nearby or easily spotted.

Toxicity Of Brown Recluse Venom

The desert recluse is one of the two most common types of recluse spiders in Arizona. It is often mislabeled as a brown recluse in Western Arizona, Southern California and the southern tip of Nevada. However, like its brown recluse cousin, the desert recluse has the same identifiers such as having only six eyes (which appear as three eyes at first glance) and a violin-shaped design on the back of its head.

Of the four recluse spiders in the United States that are venomous, all of them produce cytotoxins , which cause tissue death. Along with infection, tissue death resulting in necrosis is the biggest concern when dealing with brown recluse bites. It’s believed that Loxosceles laeta , also known as the Chilean recluse spider , is the most dangerous of the species. Though it is not native to the United States, this spider has been established in parts of California and Florida, and one was even found in Massachusetts despite its preference for warm climates. Discerning between recluse spiders may come down to your ability to identify them — taking a photo is the most foolproof way to do this.

Should You Go To The Hospital For A Brown Recluse Bite?

When it comes to seeking serious medical attention for a bite, we spoke to the Editorial Administrator for Southwestern Entomologist , arachnologist Armando Rosario-Lebrón, who says it always makes sense to see a doctor for an unknown bite or injury.

“Don’t take a gamble on your health. Recluses can be potentially dangerous,” he shares. “Now, let me be incredibly clear: it is highly unlikely you will ever encounter a brown recluse, let alone experience a spider bite, in your lifetime. The name ‘recluse’ really speaks to their nature. These animals do not like disturbed environments and prefer quiet, undisturbed locations.”

Rosario-Lebrón, who is also an educator and outreach specialist in biodiversity, also says that it’s important to remember to shift our perspectives. When it comes to venomous insects such as the brown recluse, the fear of the bite is often what overrides logic.

I think it’s important to remember you are a Goliath kaiju compared to this animal. It is terrified of you and wants to be left alone.

Rosario-Lebrón says that medical professionals often diagnose recluse bites because it’s the most common and prevalent cause of a dynamic necrotic wound they’ve been taught about. “Doctors in areas where brown recluses are common will often be much more conservative because they understand how rare a recluse bite is,” he says. “By comparison, doctors in areas where recluses do not exist may diagnose several recluse bites in a month, sometimes with more bites than recluses ever found in that state!”

At The Time Of The Bite: Within The First Few Minutes

In the event you are bitten by a brown recluse, pain can range from mildly uncomfortable such as a bee sting, whereas some people feel nothing and don’t realize they were bitten. For most, the pain is akin to a pinprick, quickly accompanied by redness and a lingering sting. Occasionally, if the bite was deep enough, fang marks can be visible at the bite location.

Bite Symptoms: Within The First Few Hours

Severe Symptoms: 12 Hours Or More

Brown recluse bites are known to take some time before more severe signs of infection or necrosis are apparent. This slow development means that you may feel fine, but find that the bite has taken a turn for the worse the following day. Experts recommend monitoring the bite site for at least 12 hours.

In The Clear: After 96 Hours

The total recommended time to observe a bite is a full 96 hours. After that, necrosis, infection, and other serious effects of the venom can be ruled out. At this point, monitoring the wound and ensuring it remains unchanged with no signs of necrosis are the only required actions. If the bite has turned into an open sore, it should be treated like an open wound and kept clean, with care taken to allow it to close up and heal.

Worst-Case Scenario

These are signs of a severe full-body reaction after being bitten by a brown recluse. If any of these show up following a bite, you should go to the hospital immediately as they may be early signs of hemolytic anemia.

Necrosis is another dangerous side effect of a brown recluse bite and the onset of this is not as quick as hemolytic anemia. Necrosis can develop several days after a person is bitten, but the timing can vary depending on the individual and the severity of the bite. This makes it difficult to determine whether there’s any immediate danger, according to the Illinois Department of Public Health . IDPH also states that this happens in less than 10% of brown recluse bite cases, thus truly making it a worst-case scenario that most people will not experience.

Treatment In The Event Of A Worst-Case Scenario

For more severe bites, doctors at Columbia University recommend treatment of the site itself. If the wound is severe enough that necrosis has attacked the surrounding skin, a skin graft can help remove the dead cells before replacing them with new, healthy skin. If this is not done, necrosis may spread.

Another option for rare cases in which a bite has escalated in severity is hyperbaric oxygen therapy. This treatment increases the blood oxygen level, which helps to slow the rate at which tissue dies due to necrosis. This treatment can also encourage faster healing while also fighting infection, making it a viable option for anyone with a severe spider bite. However, since the treatment requires access to a hyperbaric chamber, it may not be available at smaller hospitals.

Best-Case Scenario

“Ninety percent of all brown recluse bites heal without severe scarring, and many cause only a small red mark that heals without incident,” says Rosario-Lebrón, adding that many bullseye-type bites, such as those left by ticks, are often misdiagnosed as spider bites. “Especially given the risks, this is not something you should consult the grand doctor of Google about.”

Final Thoughts: How Big Of A Risk Do Brown Recluses Really Pose To Humans?

According to Rosario-Lebrón, brown recluses — like many other arachnids — are wildly misunderstood.

“I used to run a spider course for children under 8 years old. Most kids would love to touch tarantulas and even pick up small spiders. They were overjoyed and seemed to have a genuine curiosity that drew them to these animals,” he shares. “I remember watching as their parents looked on in horror in some cases. By the time high school students took the same course, I once had an entire classroom run screaming to the back of the room because the tarantula was removed from its enclosure. What does that tell you? A lot of this is irrational; it’s a learned fear and an unfortunate one for some of the most important animals in our ecosystem.”