If you have ever heard of a black widow spider, then you probably think of a dangerous spider. In fact, it is only the female black spider that is dangerous to humans.
It can be confusing as there are a number of spiders that look just like the black widow, some are completely harmless, while others are also considered dangerous.
Wondering if it was a black widow you saw? Continue reading to find out more.
Table of Contents
What Are Black Widow Spiders?
In North America, there are a number of black widow species:
- Southern black widow (Latrodectus mactans)
- Western black widow (Latrodectus hesperus)
- Northern black widow (Latrodectus variolus)
Female black widow spiders are the most dangerous and are easily identified by the red hourglass on her belly with a shiny black body.
Males, on the other hand, have red and yellow bands and spots on their backs. They also have longer legs and smaller bodies.
Juveniles look like males.
How to Identify a Female Black Widow Quickly
- Bright red hourglass marking on the underside of the abdomen
- Shiny black in color
- Measures up to 13mm in body length, excluding the legs.
Black Widow Bites
If bitten by a female black widow, you can experience some unwelcome side effects due to her toxic venom.
Symptoms include nausea, dizziness, sweating, pain at the bite site, high blood pressure, chest pains, salivation, and headache. In addition to this, other symptoms include itching, rash, eye-watering, problems breathing, and swollen eyelids.
People might develop many different symptoms after getting bitten by a black widow spider. Some of these symptoms might be mistaken for the symptoms of another disease, especially if the patient in question has a tendency to get sick.
In the event you think you have been bitten by a black widow, it’s recommended you seek urgent medical treatment at your closest emergency room.
If there is someone with you, ideally they should capture the spider in a jar and take it with you to the emergency room.
Where You Can Encounter Black Widow Spiders
Black widows are usually found where there is sparse vegetation, hollow logs, and piles of debris.
They are seldom encountered indoors, though they may be brought into the home in firewood or other items that have been sitting outside.
These are nocturnal spiders, that will hide in their nest during the day. At night they prowl for food on their webs, hanging upside-down waiting for prey to pass by.
Black widows are almost everywhere in the United States.
Northern black widow spiders are reported in northern states such as North Carolina, South Carolina, Virginia, Maryland, Missouri, New Jersey, Texas, Kentucky, Arkansas, New York, Pennsylvania, Illinois, and more.
As in the below map, southern black widows are often reported in the southeast states such as Texas, Florida, Oklahoma, Louisiana, Alabama, Georgia, Mississippi, South Carolina, North Carolina, Virginia, and more.
Western black widow spiders are often found in California, Texas, New Mexico, Arizona, Nevada, Oregon, Washington, Utah, Idaho, Colorado, and more.
Black Widow Eggs and Spiderlings
Black widows have a small sac that contains their eggs. The egg sac is only one centimeter and holds up to two hundred and fifty eggs, which take around two weeks to hatch. The spiderlings stay in the sac until their first molt.
Note that this is when the female black widow is mot protective and will bite if you go near the egg sac.
Spiders That Look Like Black Widows
There are a number of spiders that can be mistaken for the black widow, these include:
1. Brown Widow
Scientific name: Latrodectus geometricus.
Common name:brown widow, brown button spider, grey widow, brown black widow, house button spider, geometric button spider.
The brown widow is related to the black widow but is not as dangerous.
Brown widows have black and white patterns on the side of their abdomens and an orange to yellow hourglass shape.
These spiders are smaller and lighter in color than the black widow with stripes on the legs.
If you are bitten, their bites are painful but are not considered dangerous.
Brown Widow vs Black Widow
- The hourglass shape is orange to yellow in color and not bright red
- They have black and white on the side of the abdomen, the black widow is completely black and shiny
- Smaller in size than the black widow
2. Triangulate Cobweb Spider
Scientific name: Steatoda triangulosa.
Common name:triangulate cobweb spider, triangulate bud spider.
Triangulate cobweb spiders are common house spiders that tend to hide in the dark corner of outbuildings.
They have poor eyesight, relying on their sense of touch, feeling vibrations to find their prey.
They are small in size and are not aggressive towards humans.
These spiders are considerably smaller than the black widow, growing to 6mm in body length with a brown to orange head region and yellow legs.
Their bulb-shaped abdomen is cream with purple to brown zigzag patterns.
Triangulate Combfoot vs Black Widow
- They are half the size of the female black widow, growing to only 6mm
- Their color is cream with yellow legs and orange head region, compared to the shiny black of the black widow
- They have brown to purple zigzag patterns on their abdomen.
3. Noble False Widow
Scientific name: Steatoda nobilis.
Common name: (noble) false widow.
Noble false widows are the largest in the false widow species and are often found near homes.
They have dark brown on the front of their bodies and their legs.
The large bulb-shaped abdomen can vary in cream with dark brown, sometimes there are very few markings if any.
Bites from the noble false widow are rare, they are not an aggressive species.
They grow to a similar size as the black widow, of up to 14 millimeters.
Noble False Widow vs Black Widow
- Rather than being shiny black, these spiders are dark brown with brown legs and cream to brown markings on their abdomens.
4. False Black Widow
Scientific name: Steatoda grossa.
Common name:cupboard spider, dark comb-footed spider, brown house spider (in Australia), false widow, false black widow.
False black widows are found throughout the United States and are sometimes called cupboard spiders.
Their body shape and color are similar to a black widow, as are their webs.
It is considered medically significant if you are bitten by a false black widow, even though their bite is not as dangerous. It will cause severe pain.
The female has a large bulb-shaped abdomen with a body-color that ranges from brown to black or purple.
They do not have the red hourglass warning sign on the underside of their abdomens.
False Black Widow vs Black Widow
- No red hourglass on their undersides
- Colors tend to be more of a purple-black or brown than shiny black
5. Red Widow
Scientific name: Latrodectus bishopi.
Common name:Red widow.
Red widows are endemic to central and southern Florida, where this spider prefers a sand dune habitat.
They have an orange to red head space with a black abdomen, that has yellow rings that outline a row of red spots.
The legs are red.
They do not have the famous red hourglass on their underside, this is replaced with two small red marks.
This is considered a venomous spider, but there are no bites recorded as it seldom comes into contact with people.
Red Widow vs Black Widow
- Red widow has an orange to red head space (cephalothorax)
- The black abdomen has yellow rings and red spots
- There is no red hourglass on the underside.
6. Boreal Combfoot
Scientific name: Steatoda borealis.
Common name:Boreal combfoot.
The Boreal combfoot spider is often confused with the black widow, though they have a red to brown colored abdomen with a T-shaped marking on the front end. The underside is lighter than the top of the abdomen.
They are encountered East of the Rocky Mountains, though they are known to be moving south. They are usually found under stones, in rock crevices, and outbuildings.
They are significantly smaller than the black widow, growing to only 7mm in body length.
Boreal Combfoot vs Black Widow
- Considerably smaller than the black widow, growing to 7mm in body length, excluding the legs
- Red to brown colored abdomen with a T shape, rather than the shiny black of the black widow.
- Lighter coloration on the underside compared to the upper side of the abdomen
- No red hourglass on the underside
7. Rabbit Hutch Spider
Scientific name: Steatoda bipunctata.
Common name:Rabbit hutch spider.
Rabbit hutch spiders are common in North America and are often encountered close to homes, especially in sheds and basements.
They are similar in shape to the black widow and are often mistaken as the black widow, though they are not as dangerous to humans.
They have bulb-shaped abdomens that are brown with a broken line down the center and another on the anterior portion of the abdomen. They have an interesting infinity pattern on their underside.
They can grow to around 7mm in body length.
Rabbit Hutch Spider vs Black Widow
- Brown abdomen with a pale line down the center and on the anterior side of the abdomen
- Infinity shaped symbol on the underside
- Smaller than the black widow
8. White-spotted False Widow
Scientific name: Steatoda albomaculata.
Common name:white-spotted false widow.
The white-spotted false widow is a common cupboard spider that spins its webs in undisturbed areas of the home and garden.
They are often mistaken for the dangerous female black window, though they are significantly less harmful.
They come in a variety of sizes and colors, which range from red plum and satin black to pale brown. Their bulb-shaped abdomens have white, beige, or orange markings.
White Spotted False Widow vs Black Widow
- Sandy brown to black or plum red in color
- White, beige, or orange markings on the abdomen
- No red hourglass on the underside
9. Redback Spider
Scientific name: Latrodectus hasselti.
Common name:redback spider, Australian black widow.
The redback spider has slender legs with the front pair being longer than the rest with a one centimeter body length.
They have a rounded abdomen which is brown or deep black with red to orange stripe on the upper surface, along with an hourglass shape on the underside.
Some females have plain black abdomens without any marketings.
Spiderlings are gray with darker spots.
Males are light brown in color with white markings on the upper sides of the abdomen and a pale hourglass on the underside.
This is also considered a dangerous spider and if bitten, you should seek medical treatment as the pain can be intense in the bite area.
Redback Spider vs Black Widow
- Red to orange stripe on the upper abdomen
- Scarlet hourglass on the underside, darker than the bright red of the black widow
10. Katipō
Scientific name: Latrodectus katipo.
Common name:katipo.
This medium-sized spider grows to around 8mm with a leg span of 32mm.
The female has a large black bulb-shaped abdomen, similar to the size of a pea with slender legs.
They also have a white-bordered orange to red stripe on the back.
Their abdomen is velvet black, which looks silky in appearance, rather than the shiny black of the black widow.
They have a red patch or partial red hourglass on the underside of the abdomen.
There are variations in this species which are completely brown with yellow or dull stripes and cream-colored spots.
Katipo vs Black Widow
- Smaller in size, growing to 8mm in body length
- Orange stripe with white border on the back
- Red patch or partial hourglass shape, rather than the perfect red hourglass danger sign seen in the black widow
11. European Black Widow
Scientific name: Latrodectus tredecimguttatus.
Common name:Mediterranean black widow, European black widow.
The European black window is best identified by the thirteen spots on the dorsal abdomen. The spots are usually red, but they can also be orange or yellow.
Females can grow up to 15mm in body length and the female is considered dangerous to humans and pets.
A bite from this spider is considered medically significant and can be fatal in some rare cases.
European Black Widow vs Black Widow
- Slightly larger than the black widow at 15mm
- 13 yellow, red, or orange spots on the underside of the abdomen, rather than the red hourglass of the black widow
12. South American Black Widow
Scientific name: Latrodectus curacaviensis.
Common name:South American black widow, Brazilian black widow, Araña del trigo.
The South American black widow female can grow up to 17mm in body length with the body and legs being black and red, which helps you identify them apart from the black widow.
Males are white or brown in color.
They are a nocturnal species and are not normally aggressive towards humans, though females will attack to protect their eggs.
Unlike the black widow, a bite from the South American black widow usually only affects children and those with respiratory problems and cardiovascular issues.
South American Black Widow vs Black Widow
- Black and red on body and legs
- Larger than the black widow
13. Domestic House Spider
Scientific name: Tegenaria domestica.
Common name:barn funnel weaver, domestic house spider.
The domestic house spider has an elongated body with flattened head space.
They are smaller than the black widow, growing to 11.5mm in body length.
They are dark orange to beige or brown in color with striped legs and two dull black stripes on their heads. The abdomen in brow, beige and gray mottling with a chevron pattern.
Domestic House Spider vs Black Widow
- Smaller in size, growing to 11.5mm
- Dark orange, brown or beige in color, rather than the shiny black of the black widow
- Striped legs, compared to the all-black legs of the black widow
- Mottled abdomen
- Chevron patterning on the abdomen
14. Black House Spider
Scientific name: Badumna insignis.
Common name:black house spider, common black spider.
The black house spider female can grow to 18mm in body length with a 30mm leg span. They have a dark brown to black head space and legs with a charcoal gray abdomen, along with being covered in velvet hair.
While they are venomous, they are not considered dangerous with bites being rare. If you are bitten, you can expect pain with localized swelling.
Black House Spider vs Black Widow
- Larger in size, up to 5mm larger than the body length of the black widow
- Dark brown to black head space with charcoal gray abdomen
- Covered in velvet hair
- No red hourglass on the underside
Summary
The black widow is shiny black in color without any patterns, dots, or stripes. The underside of the female has a large red warning sign, an hourglass shape. These are the two things to bear in mind if you think you have been bitten or seen a black widow.
While there are many spiders you may think are black widows, the other spiders usually have different colors, they are different sizes and don’t have the bright red hourglass on their underside.
If you think you have been bitten, seek urgent medical treatment at your local emergency room and if you can, take the spider with you to help the medical team identify the best course of treatment.
Further Reading:
- 19 Spiders that look like crabs.
- 14 spiders that look like ants.
- Spiders that look like scorpions.
FAQs
What spider looks like black widow? ›
The false widow spiders (Steatoda spp.) form a group of species that, because of their general resemblance to the much more notorious black widow spiders (Latrodectus spp.), can cause concern when found in the UK. Although they resemble black widow spiders, they are not as harmful.
What other spiders look like false widows? ›Mistaken identity
Two of the most common are the missing sector orb weaver (Zygiella x-notata) and the lace webbed spider (Amaurobius sp.). Both species, like false widows, are found all over the UK.
Indeed, false widows are capable of inflicting a painful bite, but they are not usually aggressive to humans. A bite from this type of spider is rare, and most of the time, it occurs in defensive situations such as being accidentally squashed or feeling threatened.
Is this a false widow spider? ›False widows will usually have a narrow white or slightly lighter band towards their head. While females have a globular shiny abdomen, the male abdomens are smaller and less rounded. The native rabbit hutch spider and cupboard spider are smaller than the noble false widow, around 5-7mm and 10mm respectively.
What do I do if I find a false widow spider? ›If you do see a noble false widow spider, you can remove it by placing a glass or other receptacle over the top of them, and then sliding a piece of card under the container. Pick it up carefully and release it outside, preferably a little way away from the property if possible.
Where are false widows? ›Noble false widows are not native to the UK, but are thought to have arrived from the Canary Islands in banana boxes in the late 1800s. Populations became established along the south coast and have since spread north, likely aided in their expansion by global warming. The other two species are both native to the UK.
Do false widow bites hurt? ›As a guide though, the bite has been compared to a wasp sting with a similar stinging, burning pain initially. With time at least some degree of swelling is likely to occur often accompanied with local numbness. The venom of the false widow and other spiders in the Steatoda group can also cause steatodism.
Does a wolf spider bite hurt? ›Since wolf spiders are large, their bite may be painful. If you have mild pain, swelling, or itchiness around the bite, it shouldn't last long. The pain should go away within minutes. The swelling should go down slowly, and the itching may last a few days as the skin heals.
How long does a false widow spider live? ›The life cycle lasts for approximately 1-2 years, with the female living longer than the male. Mature and reproductive male spiders are found in summer and autumn, mature females can be found all year round and egg sacks are laid from spring through to autumn.
Do false widow spiders play dead? ›Real false widow bites are unlikely since their main defences are hiding or playing dead. Hardly terrifying, but it's still best not to handle them.
Are skull spiders real? ›
Steatoda nobilis has a brown bulbous abdomen with cream coloured markings that are often likened to the shape of a skull. Their legs are reddish-orange. Both female and male S. nobilis can be distinguished from other spiders of the same genus by their large size and typical colouration.
What spider is the most poisonous? ›Sydney funnel-web spider. According to the Guinness World Records, the Sydney funnel-web spider, Atrax robustus, is the most dangerous spider to humans in the world. Native to Australia, this poisonous spider is found in moist habitats such as under logs or in gardens.
What spider has a skull on its back? ›For those with vivid imaginations the white markings on the black back of a noble false widow spider (Steatoda nobilis) can look like a skull and crossbones, or in other cases just a skull.
How do I identify a spider? ›But here are a few common characteristics to help you distinguish spiders from other insects: All spiders have eight legs and six to eight eyes. Spiders have two body regions: the cephalothorax and the abdomen. Male spiders are normally smaller and have different color markings than females.
What kind of spider has a face on its back? ›T. grallator gets its vernacular name of "Hawaiian happy-face spider" from the unique patterns superimposed on its abdomen, specifically those that resemble a human smiling face.
What spray kills false widow spiders? ›If however the thought of dualing in hand-to-hand combat with a false widow spider is too much to bare an insecticidal (like fly spray) areosol licensed for use on spiders will do the job. With effective at ranges of several feet you'll find a short squirt will make them history.
Do false widows move fast? ›False widow spiders are not fast moving or aggressive, so have no reason to bite unless they are provoked or feel threatened. Common sightings have been in greenhouses, sheds and homes as they search for warm shelter.
Are there other types of widow spiders? ›There are two species of widow spiders in California, the western black widow and the brown widow. Both are in the genus Latrodectus and are characterized by a similar body shape, reclusive habit, and irregular cobwebs.
What happens if you get bitten by a false widow? ›The symptoms are usually no more severe than a bee or wasp sting, but a handful of those who have been bitten have described more acute symptoms including throbbing pain, swelling and tingling in the fingers. They have a glossy sleek outer surface with coloured markings on the back and abdomen.
What does a bite from a false widow look like? ›A false widow bite looks like most insect bites. A small hole, or the sting itself, may also be visible. The lump may have an inflamed (red and swollen) area around it that may be filled with fluid. It's long been understood that, though false widows do have a venomous bite, the venom is not particularly potent.
Are black widows in the UK? ›
Black widow spiders are not found in the UK but are very rarely unintentionally imported.
What spider looks like a black widow but has white spots? ›False Widow Spider (Steatoda washona)
The false black widow spider has a bulbous black abdomen with several white spots, orange-brown legs, and a brown head. However, it's easy to distinguish this spider from a true black widow because it only has white spots on its black abdomen, not red markings.
Black house spiders are venomous, but are not considered dangerous. They are timid and bites from them are infrequent. The bite may be excruciatingly painful and cause local swelling. Symptoms such as nausea, vomiting, sweating and giddiness are occasionally recorded.
What happens if a cellar spider bites you? ›Cellar spiders are not poisonous, although the correct terminology would be venomous, which they also are not. Cellar spiders are not medically important spiders because they are not known to bite people. Nonetheless, an urban myth persists that cellar spider venom is among the deadliest on the planet.
Are skull spiders real? ›Steatoda nobilis has a brown bulbous abdomen with cream coloured markings that are often likened to the shape of a skull. Their legs are reddish-orange. Both female and male S. nobilis can be distinguished from other spiders of the same genus by their large size and typical colouration.
Does a wolf spider bite hurt? ›Since wolf spiders are large, their bite may be painful. If you have mild pain, swelling, or itchiness around the bite, it shouldn't last long. The pain should go away within minutes. The swelling should go down slowly, and the itching may last a few days as the skin heals.
What spider has a skull on its back? ›For those with vivid imaginations the white markings on the black back of a noble false widow spider (Steatoda nobilis) can look like a skull and crossbones, or in other cases just a skull.
Is the zebra spider poisonous? ›They do produce venom, which is used to subdue their prey, but this spider's venom is likely only to cause minimal injury to humans since the spiders are so small.
How long does a false widow spider live? ›The life cycle lasts for approximately 1-2 years, with the female living longer than the male. Mature and reproductive male spiders are found in summer and autumn, mature females can be found all year round and egg sacks are laid from spring through to autumn.
Do false widow spiders bite? ›They can give a painful bite which has been likened to bee or wasp stings. However bites are rare and usually result from handling the spider roughly or from a spider being trapped between clothing and skin.
What are the big black spiders in my house? ›
The most typical black spider you're likely to come across indoors is the black house spider. This small black or dark brown spider has a plump body and eight fat legs. Like the black widow, the common black spider has a nasty bite that may cause swelling and nausea.
Should I leave black house spider? ›Threats. Black house spiders are venomous, but are not considered dangerous. They are timid and bites from them are infrequent. The bite may be excruciatingly painful and cause local swelling.
Are daddy long legs poisonous? ›"Daddy-Longlegs are one of the most poisonous spiders, but their fangs are too short to bite humans"
What does a hobo spider bite look like? ›A bite from a hobo spider may be unnoticeable at first, but it'll cause pain and numbness within 15 minutes. After 1 hour, the site will start to turn red. In 8 hours, it'll become hardened and swollen. After 24 to 26 hours, the wound may discharge fluids and eventually turn black.
What do daddy long leg bites look like? ›What Happens if a Daddy Long Legs BITES You? - YouTube
Are banana spiders? ›What are banana spiders? Banana spiders are large spiders found throughout the southeastern United States. Banana spiders receive their name because of the yellow/golden-colored silk they create to make their very large webs which they use to catch flying insects, their main food source.