Are Black Widows Poisonous or Dangerous?

Written by Jennifer Gaeng
Updated: October 25, 2022
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Black widow spider on white background
Black widows live all across the U.S. in urban areas but prefer grasslands, woodlands, and deserts.

©Protasov AN/

Black widow spiders, or Latrodectus, are a group of arachnid spiders. Australia, Africa, and South America all have Latrodectus spiders. Black widows live in urban areas, woodlands, deserts, and grasslands in the United States. They are most notable for their striking appearance and alleged propensity to eat their own kind. Have you ever wondered if this is true? How dangerous is the black widow really and could a bite from one be poisonous? Are black widows deadly? Find out here!

Are Black Widows Dangerous?

Most Dangerous Spiders
The black widow spider is not dangerous unless provoked.

©Sari ONeal/

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The black widow spider is a shy and non-aggressive species of spider, not considered dangerous unless provoked. However, if they feel threatened, black widow spiders will bite, but they won’t go out of their way to attack you. They will only bite in self-defense or in response to a perceived threat from another animal.

Spiders such as black widows prefer to hide out in dark places, such as stacks of rocks or leaves. To avoid getting bitten by a black widow spider, don’t move or disturb these mounds without gloves. People who are moving things out of dark basements and garages should also wear gloves. These places may be home to black widow spiders.

Are Black Widows Poisonous?

Weakest animals black widow spider
Although black widows do have venom, a bite from one is very rarely fatal.


Although black widow poison is fifteen times stronger than rattlesnake venom, its bite rarely kills humans. Because spiders have less venom than snakes, their bites are only dangerous to the incredibly young and the old.

Black widows use their venom to subdue and consume prey. Toxin alpha-larotoxin, found in widow venom, induces unfavorable effects in its victims. Although the black widow’s bite is small, this venom overwhelms nerve cells, producing swelling and extreme agony.

Only adult females can bite people. Males and juveniles either don’t bite humans or their mouthparts are too small or weak to do so.

Toxic symptoms of this genus include nausea, excessive perspiration, severe abdominal and back pains, muscle aches, hypertension, and diaphragmatic paralysis (difficulty breathing). The Occupational Safety and Health Administration states that pain might last 8 to 12 hours, and other symptoms can last days.

What Do Black Widows Look Like?

Australian Red-back spider
Female widows are black with red markings in their abdomen, whereas males are lighter with more pink-colored patterns.

©Peter Yeeles/

Male and female black widow spiders look quite different, as is the case with many other spider species.

The females of all black widow species have shiny black bodies and a red hourglass-shaped pattern on the underside of their round abdomen. The hourglass markings on females can also be orange-yellow. The female black widow is around 1.5 inches long.

Compared to darker-colored females, males have smaller abdomens with lighter red or pink-colored patterns. Male black widows are less than half the size of females, with a body length of up to 0.5 inches.

How Serious Is A Black Widow Bite?

A black widow’s bite is venomous, yet many people have no or minor health issues. The AAPC received roughly 1,866 black widow bite reports in 2013. Only fourteen had severe symptoms, nonfatal.

The black widow spider’s venom is neurotoxic. Some people are mildly affected, while others are severely afflicted. You may experience significant pain, burning, swelling, and redness.

What to do if you think you’ve been bitten by a black widow spider:

Anyone who has been bitten by a black widow spider, or who fears they have been bitten, should seek emergency medical attention.

Before you go to the hospital, or even while you’re on your way there, there are some things you can do to prepare:

  • Use soap and water to properly clean the bite.
  • Take 10-minute pauses between applying a wet or moist ice pack to the affected area.
  • If at all feasible, elevate the site of the bite.

You should get to a hospital as soon as possible but try not to panic. Antivenom for black widow bites is available; it works on all black widow species and relieves pain within 30 minutes.

Do Female Black Widows Eat Their Mates?

Apex predator: black widow spider

©Jay Ondreicka/

If you want to know whether the black widow female eats her mate, the answer is sort of. Females rarely engage in sexual cannibalism. The Southern Hemisphere is home to the only Latrodectus species where mate cannibalism is the norm rather than the exception. However, once they emerge from their eggs, black widow babies often consume their freshly hatched siblings.

What Do Black Widows Eat?

What Do Black Widows Eat - Male and Female Black Widow
Black widows primarily eat other smaller insects.


Insects and arachnids are the primary diets of black widows, although they have been observed to catch and eat small vertebrates like snakes and lizards as well.

How Do Black Widows Trap Their Prey?

Apex predator: black widow spider
The black widow uses its venom to paralyze its prey.

©Jay Ondreicka/

The black widow spider paralyzes its prey with a poisonous bite once the animal is caught in its web. The spider release enzymes into their target’s body when the prey is no longer moving then carries its prey away to be devoured.

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About the Author

A substantial part of my life has been spent as a writer and artist, with great respect to observing nature with an analytical and metaphysical eye. Upon close investigation, the natural world exposes truths far beyond the obvious. For me, the source of all that we are is embodied in our planet; and the process of writing and creating art around this topic is an attempt to communicate its wonders.

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