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Their very name often creates fear in people. The black widow spider has a reputation for being deadly, dangerous, and poisonous. All of those things are correct to some degree, but like most things, some of the bad reputation comes from legend and are not necessarily true.
Of course, the last thing you want is a bunch of black widows around your house so your pet or child can stumble into them, but the fear that they instill is mostly due to a lack of knowledge.
As always, the more you actually know about something, the better you can deal with them. If you are finding too many black widows or other spiders around your property, then don't try to deal with them on your own. Contact your local Western Exterminator office today.
Color
This is a classy breed of spiders. While black or brown, they have red patterns and markings. Females have two reddish triangular markings on their undersides that resemble an hourglass or sometimes only a single triangle. There are usually red markings above the spinnerets. Males usually have a colored pattern on top, and a row of red spots along with white lines or bars extending to the sides. As for spiderlings, they are usually orange or white, with markings on top, as well as one or two reddish ones beneath.
Black widow spider facts
The black widow is actually a name given to a wide range of spiders located across the globe, and all of whom are part of the genus of spider known as Latrodectus which are in the larger family of Theridiidae (also known as comb-footed spiders, due to the special comb-like bristles on their hind legs that help them weave their strong, tangled webs). There are actually 32 species known as widows all over the planet. The most well-known species in North America is Latrodectus mactans.
Black widows are relatively small, measuring between three to 10mm in length, with the females much larger than the males. Their legs are long and slender, helping them navigate their irregular webs.
They are predators, and their venom is potent. Reportedly, the poison of a North American black widow is 15 times stronger than that of a rattlesnake and can cause paralysis of the lungs in extreme cases.
Black widow spiders are very shy and non-aggressive. They only attack in defense when their webs are disturbed or when they are handled. They weave very disorganized webs in hidden places, much like the brown recluse spider. Widows try to avoid people and animals and don’t even like other spiders much unless it’s mating season.
Most people will say that a black widow is a shiny black with a red hour-glass shape on their abdomen, but that is not always the case. Although they are likely to have red markings on their abdomen, it is not always in the hourglass shape. Sometimes, they can be triangles or other shapes.
Widows got their name from their habit of mating with the much smaller, harmless, male widows and then devouring them. Spider cannibalism is common, and this does happen, but again not always. Male widow spiders have been seen seeking mates that have recently eaten, seeking webs with the carcasses of insects they have eaten.
Where do black widows live?
On occasion, black widows can be found inside homes, but they generally prefer the outdoors. They prefer undisturbed locations, so unless they are seeking warmth or are accidentally brought inside on firewood, they’ll likely stay outside. Black widows build their nests in crevices, by doors and vents, woodpiles, or in other places that might also be attractive to other insects. Easy access to a meal is key.
The spiders are nocturnal and hide in their nests during the day. At night, black widows will prowl their webs, looking for food. They also like to hang upside down in their webs while waiting for prey.
Black widow eggs
Black widow spider eggs are contained inside of a small sac. Each sac, with a diameter of only about 1 centimeter, can contain anywhere from 200 to 250 eggs and will hatch in approximately 2 weeks. The eggs hatch within the sac, and the “spiderlings” remain there until after their first molt. Female black widows may produce up to 20 sacs in their lifetime, of which they are very protective. When tending to their egg sacs, they may be more likely to bite in defense of their offspring.
Black widow bites
Black widows do not go hunting for humans. They prefer to eat other insects, and their babies are even known to devour each other for nutrients. Only the strongest survive to leave the black widow web and nest and move on.
Humans are generally bitten when they run into the webs or trying to handle the spider. Children, the elderly, and those with health concerns are more likely to respond negatively to the bites. For most of us, the bites are not dangerous but can be painful.
The truth is that the widow is much, much smaller than a human. Although they have poison-filled fangs, the amount that they can deliver to a human is very small. For most people, the venom may cause discomfort, and medical attention is recommended, but they will recover just fine. The average black widow just cannot inject enough venom to bring down a normal, healthy human being.
Black widow bite symptoms
As the only spider in the United States that carries a neurotoxic venom, black widows deliver an uncomfortable bite. You may or may not feel the pinprick sensation of the bite, but a halo-like mark will soon appear at the site, possibly with a set of two fang marks in the center. Within 1-2 hours, black widow bite symptoms will begin. Cramping at the site of the bite and moving outward to the stomach, chest, and back may be accompanied by a headache, nausea, dizziness, and sweating.
In more grave cases, cardiac symptoms and localized paralysis or weakness may occur. The severity of the symptoms varies depending on a number of factors including but not limited to the condition of the bite victim, how many bites there are, and how much venom was injected. Severe cases can be treated with antivenom , which neutralizes the venom and helps alleviate symptoms.
How dangerous are black widow spiders?
Black widow spiders have a bad reputation, but they’re not as dangerous as you might think. While their venom is powerful, bites are rare and usually happen when the spider feels threatened. Their venom affects the nervous system. However, fatal bites are extremely rare, especially with prompt medical treatment.
Most healthy adults recover with little to no lasting effects. If bitten, it's important to seek medical attention, especially for children, the elderly, or those with weakened immune systems.
What do black widow spiders eat?
These are skilled hunters who rely on their spider webs to catch food. As a predatory arthropod, the black widow mainly eats insects like flies, mosquitoes, beetles, and grasshoppers. Once prey is trapped in its web, the black widow quickly bites and injects venom, which paralyzes the insect. The venom breaks down the insides of the prey, making it easier for the spider to consume. Sometimes, if food is scarce, they may even eat other spiders—including their own kind.
How to get rid of black widow spiders
Black widows are venomous, and handling them yourself is risky. The safest way to get rid of black widow spiders and prevent them from coming back is with professional pest control. At Western Exterminator, our spider removal technicians are trained to know how to find and handle black widows.
Types of black widows
In California and places out west, you are more likely to see the North American Black Widow spider (Latrodectus variolus). They are located all across the country, from the humid areas of Florida to the Midwest and all the way up to Northwestern states. They have even been found in Canada.
There are southern black widows, too. They look similar to the North American version and are black with red markings on the abdomen. They are generally found in the more hot and humid southern states.
Spiders that look like black widows
Two spiders that are commonly confused with black widows are the false black widow and the brown widow.
- False black widows are smaller and have no red coloration. They like the indoors much more than black widows do, so they are more frequently involved in human bites. Luckily, their venom is mild and the symptoms of a false black widow bite can be likened to those of a yellow jacket sting.
- Brown widows are also smaller than black widows, and as their name suggests, they’re brown (not black). Their shade of brown can vary significantly from light tan to a very dark brown. In the case that they are almost black in color, they are more of a flat black than the shiny black of a black widow. Brown widows are most often confused with immature black widows, but brown widows are not nearly the threat that black widows are. Their toxicity is not much greater than that of your common house spider.
Avoid the bite
During the warm summer months, it is possible that black widows will get more active. This is the time of year that the widows look to mate and lay their egg sacs. So, if you notice them more around your home, avoid those areas just to be safe.
More to the point, if you worry about getting bitten by black widows, call in the experts who know how to handle them and that can help make sure that they don’t come back.
Don’t be terrified of the black widow, but avoid them when you can because who really likes being bitten by a spider anyway?
If you find black widows, or any other spiders, around your home and want them removed, then be sure to contact the spider control and spider removal experts at Western Exterminator.
Frequently asked questions:
How poisonous is the black widow spider?
Black widow venom is strong, but bites are rarely deadly. Their venom affects the nervous system and can cause pain, muscle cramps, and nausea. While dangerous, especially for young children or the elderly, bites are treatable with medical care.
What happens if you get bitten by a black widow?
A black widow bite can cause sharp pain, muscle cramps, sweating, and nausea. Symptoms may last for several hours or days. Severe cases might require urgent medical treatment, but most people recover fully. If bitten, seek medical attention, especially if symptoms worsen.
Should I go to the ER for a black widow bite?
If you suspect a black widow bite, you should seek immediate medical attention.
What should I do if I see a black widow spider?
If you see a black widow, don’t try to handle it. These spiders will only bite if they feel threatened. Instead, keep your distance.
What is the survival rate for a black widow bite?
The survival rate for a black widow bite is extremely high. Fatal bites are very rare, especially with modern medical treatment. Most people recover fully, though young children, the elderly, and those with health conditions may have stronger reactions.
What is the story behind the black widow?
The black widow gets its name from the female’s habit of eating the male after mating. This behavior, called sexual cannibalism, inspired the "widow" name. Not all females do this, but it happens often enough to give the spider its famous reputation.
Is the black widow evil or good?
Black widows aren’t evil—they’re just following their natural instincts. They help control insect populations and rarely bite unless provoked. While their venom is strong, they don’t seek out humans to harm. They prefer to hide and avoid contact.
Should I be worried if I see a black widow?
It’s important to be cautious, but not panicked. Black widows usually hide in dark places and don’t attack unless disturbed. If you see one in your home, avoid it and call Western Exterminator for safe and professional removal.