Of all the common pest questions we answer, maybe the most common is, “is that thing dangerous?” People are fascinated and terrified by the idea of dangerous bugs. The less we know about the pests we’re looking at, the scarier (and more dangerous!) they tend to be. The more you know, the safer you’ll be.

To that end, we’ll be covering several of Michigan’s scariest, most dangerous pests. These are the pests that may pose a legitimate danger to people, pets, and property. We’ll start with the one people ask us about the most: the infamous brown recluse spider. Here’s everything you need to know about the brown recluse in Michigan.

What is the Brown Recluse Spider?

The brown recluse spider (Loxosceles reclusa) is a venomous recluse spider native to the southeastern US. They measure around 6 to 20 millimeters long (about the size of a quarter), and appear uniformly tan to dark brown in color. Unlike most spiders, brown recluse have six eyes instead of eight. The spider’s legs are long, thin, and covered with fine hairs. Both the legs and torso of the brown recluse lack any banding, spines, or mottling. All adult brown recluses have a distinctive dark “violin-shaped” mark on their backs, near their heads.

Like most spiders, the brown recluse is considered very shy. They’ll go out of their way to avoid humans and would rather run away than act aggressively when confronted. Most brown recluses spend daytime hiding in secluded, hidden areas and hunt for food at night. Though they build small, asymmetrical webs, they don’t use these webs to hunt their prey. Instead, they hunt prey by lunging and using their venom to immobilize and kill it. Brown recluse spiders are well-adapted to living indoors and will produce offspring in homes.

Why is the Brown recluse spider dangerous?

Why Is It Dangerous?

The brown recluse is one of three North American spiders with significantly dangerous venom. Brown recluse bites are very, very uncommon, but when they happen they can be very dangerous. Though 90% of bites heal quickly without any issues, 10% may lead to severe symptoms. Brown recluse venom is necrotic, which means it can trigger cellular death when injected into living tissue. This venom may inflict major tissue damage around the site of the bite, creating a large wound and scar.

Reactions to brown recluse bites are often delayed by 3 to 8 hours. The bite itself is painless. Hours after the bite, the victim may develop a blister or discolored lesion. The wound site will swell and become very painful. This process may be accompanied by vomiting, faintness, nausea, or cramping. Within 48 hours, necrosis may manifest. If that happens, the wound will turn purplish, then black in color. Eventually, the tissue may come away, creating a large wound. Again, it’s important to note just how uncommon this is. Brown recluses very rarely bite humans, and even when they do those bites rarely develop into lesions.

Where Does It Live?

The brown recluse is native to the southeastern US. It’s not currently considered endemic to Michigan, and sightings here are quite rare. As our climate changes, however, the brown recluse has been reported in southern Michigan more frequently. The spider is surprisingly hardy and can survive mild winters, especially if it has shelter. Brown recluse spiders may find this shelter easily, because they tend to seek it out naturally all year. The spider is most common in secluded, sheltered areas like rocky outcroppings, barns, forests, or wetlands.

Brown recluses build webs between different sources of cover to raise their young on. Many brown recluses hide beneath rocks, underbrush, or other sources of shelter that conceal them. They remain largely stationary in these hiding places during the day and come out at night. Even when foraging, the brown recluse tends to favor caution. Indoors, they’re most common in basements, attics, sheds, and other secluded locations. They may build webs in quiet corners, along awnings, or between boxes.

How can I protect myself from the Brown recluse spider?

How Can I Protect Myself From It?

You shouldn’t concern yourself with the Brown recluse (if you can help it). The spider is still highly uncommon in Michigan. In all likelihood, you’ll never encounter one. That being said, we don’t blame you for worrying about them… a little bit. Luckily, you can keep brown recluses out of your home the same way you keep out any spider. Spiders come into homes to hunt for their prey. Keeping that prey away will help keep spiders out, as well.

Spiders set up their webs near pest access points to catch other bugs making their way inside. They hunt around drafts, window and door frames, and other popular access points. Spiders are also capable climbers, which means they can find higher gaps around siding or rooftops. They tend to live in attics and basements where they won’t be disturbed. Brown recluses may hide beneath boxes, furniture, and other clutter on the floor. Depriving spiders of their prey, access points, and hiding places will help keep them out of your home.

You don’t have to be afraid of brown recluse spiders, but it never hurts to be aware of them. If you think you’ve been bitten by a brown recluse, contact your doctor immediately. If you can, capture the spider so you can show it to an expert for positive identification.

If you’re more interested in avoiding spiders than learning about them, don’t worry: we can help with that too. Give Griffin a call about your spider problems–or any other pest problems–any time. We’ll help keep your people, pets, and property safe.

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