What Is The Difference Between Black Widow And Brown Recluse Spiders?

Do you like having spiders inside your home? If you do, then you are in the minority. Most folks do not enjoy having webs in doorways, dangling spiders at the dinner table, or creepy crawlies posing silently on a wall. Even if the spiders in your home are not the poisonous kind and are simply a nuisance to have around, they can be disturbing to encounter. But when they are dangerous spiders, such as the infamous brown recluse spider or the black widow spider, then you really have something to worry about. But these two types of spiders present different issues when they come into our yards and get into our homes. Let's take a closer look and see what we can learn that will help us to tell them apart and protect ourselves from the dangers they present.

Visual Differences

When it comes to looks, these two spiders are very different. A black widow is a little larger than a dime and shiny black with a red marking on its large, bulbous abdomen. For some species of black widows, this marking looks like an hourglass. For others, it looks like dots. Whatever the shape the marking is, you're not likely to mistake a black widow for another kind of spider. It is quite distinct. You might, however, mistake a "brown" widow for another spider. A brown widow has the same large abdomen with red marking underneath, but it is a brown color.

Brown recluse are a little larger than a quarter, with tan coloration and a brown violin mark on its back. Their brown color gets them confused with wolf spiders, though it shouldn't. Wolf spiders are hairy, brown recluse spiders are not.  

Venom

These two spiders have very different venom. The venom of a black widow spider is powerful enough to take down small mammals and powerful enough to make us very sick. If you are bitten by one of these spiders, you may experience muscle cramps, chills, sweating, fever, nausea, vomiting, and more. There may also be severe high blood pressure which can cause many of the symptoms mentioned and lead to shortness of breath, seizures, and unresponsiveness. But, fortunately, it rarely leads to death in the United State, due to our robust medical infrastructure.

The venom of a brown recluse bite is associated with necrosis. While only a small percentage of brown recluse bites cause flesh to rot, it can happen. A bite from a brown recluse can be mild to intense, and the pain can last for several hours. The skin should redden and there should be a burning or itching sensation. In the center of the wound, a white blister will develop. If this turns into an open wound, it is a strong sign that necrosis is taking place below the surface. This necrosis can lead to a disfiguring wound.

If you are bitten by either of these two spiders, seek medical assistance immediately.

Habitat

A black widow spider develops a tangled web and hangs in the middle upside down. It prefers to be outside and will only go into a home accidentally. Look for this spider in brush and shaded locations. It may also hide under a rock or other object on the ground, so be careful when you turn things over.

A brown recluse spider creates a low, tangled web. It uses this web to retreat into. When this spider gets into a home, it has no trouble establishing itself. It will hide in anything that looks like a hole because, in nature, it uses the holes created by other creatures to make a den. It will also hide in stored boxes in secluded locations. Its love for boxes makes this a hitchhiking pest. Brown recluse spiders also hide in furniture and other movable objects.