Which U.S. Spiders Are Venomous to Humans?

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Nearly all spiders are venomous to some degree for the purpose of subduing their prey once they catch it. The good news is that most spider venom is not nearly potent enough to pose a significant threat to human health. However, there are two notable exceptions in the United States.

According to the CDC, the brown recluse and black widow are the two types of U.S. spiders considered venomous to humans. In other words, if one of these spiders bites you, treat the bite immediately, and don’t wait to seek medical attention.

Brown Recluse Spiders

Brown Recluse Spider

Brown recluse spiders range in color from light to dark brown, and they tend to inhabit out-of-the-way places where they won’t be disturbed, like sheds, attics, closet corners, neglected boxes, underneath furniture, and piles of leaves, rocks, or wood. You can recognize a brown recluse by the distinct, violin-shaped marking on the top of its chest.

Interestingly, a brown recluse can’t bite you unless you provide counterpressure, such as accidentally trapping the spider against your foot when putting on your shoe. The bite can sting strongly and typically develops into a white blister. However, sometimes the venom can destroy the skin tissue at the site of the bite and create a lesion. Because reactions to the venom can range from mild to severe, it’s critical to treat the bite and seek medical attention right away.

Black Widow Spiders

Black Widow Spider

Five species of black widow exist in the United States, and they’re fairly easy to recognize due to their round, black bodies and reddish “hourglass” marking on their abdomen’s underside. You can find them outdoors in woodpiles and underneath decks, but they prefer cluttered indoor environments where they can catch more prey. Exercise caution when moving boxes and other objects around dimly lit areas of your home, like the garage, attic, or basement. Black widows like to set up their webs in these areas, and most people get bitten when reaching into a web.

Black widow venom attacks the central nervous system and can cause some alarming symptoms, including stiff, aching muscles, fever, sweating, nausea, vomiting, increased blood pressure, and trouble breathing. Fatal bites are rare in adults, but you should still treat the bite and seek medical attention immediately after being bitten. Children who are bitten should be taken to the emergency room, as severe reactions and fatalities among children are more likely.

If you’re struggling with a spider infestation, please don’t hesitate to contact Greenix Pest Control. Use our online form or call us at (888) 800-7181 to learn how we can help bring you peace of mind with an effective, sustainable solution.

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