How to Identify Black Widow Spiders

Black widow spiders, named after their mating habits, are a species of venomous spider found in many parts of the world. The easiest way to identify a black widow is by observing the glossy black color and characteristic crimson markings on the female spider’s abdomen. However, the young and male spiders of this species are a bit more difficult to identify, as they have a simple brown color throughout their lives. With a little practice, you should be able to safely identify the correct black widow spider to avoid pain and the risk of falling ill from a bite.

Table of Contents

Identify colors and traces

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Look for dark red spots on female spiders. Female black widow spiders are famous for their red markings on their abdomens. This mark can be an hourglass shape under the belly or two separate triangles that look almost like an hourglass. ^{[1] X Research Source}

A type of black widow spider with a row of red dots instead of the characteristic hourglass shape.
There are many color variations of the black widow spider. Occasionally, these markings may be brown, yellow, or orange. In addition, the hourglass shape is sometimes replaced by a triangle or a dot. ^{[2] X Research Source}

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Observe that the body is glossy black and hairless. Female black widow spiders are glossy black. Black color covers the legs and abdomen of the spider, except for the red spot. ^{[3] X Source of Research} The spider’s body is hairless and smooth. ^{[4] X Research Sources}

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Observe brown and white coloration in baby and male spiders. Male and female spiders (both males and females) have smaller, brown bodies and white markings. Their appearance differs from female spiders, as they are lighter in color, usually skin color, brown or gray. There is no red hourglass like in female spiders, male spiders and baby spiders have white or yellow stripes on their backs. ^{[5] X Research Sources}

Male spiders are smaller than female spiders, almost half the size. ^{[6] X Research Sources}
The abdomen of male spiders is smaller and slimmer.
Male black widow spiders are not as dangerous as female spiders because their bites are non-venomous.

Identify body characteristics

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Check for stiff hairs under the spider’s legs. Black widow spiders have eight legs that grow from their thorax. The hind legs are covered with stiff hairs, which help spiders wrap silk around their prey. ^{[7] X National Geographic Trusted Source Go to Source}

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Notice the long legs. Black widow spiders’ legs are longer than their body size. The front legs are the longest, the three pairs of hind legs are shorter. ^{[8] X Research Sources}

The female spider’s legs are black, while the male and young spiders have brown legs.

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Consider the size of the spider. Black widow spiders are relatively small. The female spider is about 3.8 cm long, including the legs. Their body is about 1.3 cm long. ^{[9] X Research Source}

Male spiders are much smaller with a length of about 2 cm including the legs.

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Observe the round belly. Black widow spiders have a round, fat belly attached to their thorax, which lies behind their pairs of hind legs. The color of the spider’s belly matches the color of the spider’s head. You will see characteristic marks on this part of them. ^{[10] X Research Source}

Male spiders have a smaller abdomen than female spiders.

Examine the spider web

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Observe the uneven shape of the web. The web of black widow spiders is often irregular in shape. Spider silk fibers are slightly stronger and thicker than the webs of other spiders. Black widow webs look tangled, even though they are woven with great precision. Black widow webs are usually approximately 30 cm in diameter. ^{[11] X Research Source}

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Look for cobwebs in dry and dark places. If you find a web in an open location with lots of sunlight, it’s probably not a black widow web. Black widow spiders prefer to live in hidden, dark, and dry places. ^{[12] X Research Source}

Black widows are also common in areas close to the ground, so the webs overhead are probably not black widow spiders.

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Notice the spiders hanging upside down. Black widow spiders have a very unique way of resting in their webs. At night, they often hang upside down in the web to stalk their prey. During the day, they usually hide in secluded places. ^{[13] X Research Source}

If a female black widow spider was hanging upside down in the web, you would probably see a crimson color on its abdomen.

Keep safe

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Watch out for black widow spiders in dark, enclosed areas. Black widow spiders are generally reclusive spiders, usually in dark and quiet places such as nooks and crannies and secluded places in basements, sheds, attics, and outdoors. You can also find them in piles of wood, under rocks, in garbage piles, in gardens, even in shoes if you leave them outside. ^{[14] X Research Source}

Whenever working in areas known to be inhabited by black widow spiders, you need to take safety measures and observe carefully before stepping into dark corners or sticking your feet or hands into tight corners.

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Protect yourself. If you must be in an area known to have black widows, wear protective clothing. Wear gloves, long pants, long-sleeved shirt and closed shoes. This will reduce your risk of being bitten by a spider. ^{[15] X Trusted Source US Occupational Safety and Health Administration Go to source}

Spray insect repellent on clothing, such as DEET or Picaridin. These medications can prevent spiders from getting close to you.

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Contact a pest control service. If you have black widow spiders in your home, don’t try to get close to, interact with, or kill them yourself to avoid the risk of a spider bite. Instead, you should contact a pest control service. They can plan to get rid of the black widow spider for you. ^{[16] X Research Source}

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Treat the bite. Black widow spider bites can cause muscle spasms, nausea and vomiting, breathing problems, sweating, itching, swelling, weakness, and abdominal pain. These symptoms may appear within 8 hours of being bitten. ^{[17] X Trusted Source Centers for Disease Contrp and Prevention Go to source}

Seek medical attention as soon as possible.
Wash the spider bite with soap and water, then apply a cold washcloth. You can take an over-the-counter pain reliever like Tylenp. Elevate the bitten leg or arm to combat swelling.
If a child is bitten by a spider, you need to take the child to the emergency room immediately.

Advice

Black widow spiders do not have an aggressive nature. Although spider bites are dangerous, the risk of you being bitten by them is very low. However, pets are at risk of being bitten by spiders’ defensive instincts, so you should make sure there are no black widows in your home.

Warning

Regardless of your age and medical condition, you should go to the hospital if you are bitten by a black widow spider. While the common belief that you’ll die from a black widow bite is not true, the spider’s bite can cause severe pain, nausea, and difficulty breathing. In addition, it can also cause death in children, the elderly or the sick. Sometimes you don’t realize a black widow spider bite until symptoms appear, because the bite itself isn’t too painful.
All spiders are venomous by nature. However, only certain species have a significant effect.
Take great care when identifying a spider. You probably don’t want to get too close to a spider and by the time you realize it’s venomous, it’s too late. To keep a safe distance, it is recommended that you use a magnifying glass or take a photo that can be magnified. It’s a great way to see details while keeping a safe distance. Some spiders can be very aggressive and will chase even if they are not agitated or very little.

Steps