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Quick answer
The southern black widow (Latrodectus mactans) is a venomous cobweb spider of warm United States regions, especially the South, recognised by a red hourglass on the female's underside. She builds irregular webs in dark corners and woodpiles, eats insects, and is listed Least Concern; bites need medical advice but deaths are rare with care.
Top questions about the Black Widow
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Black Widow facts at a glance
- Weight 1 g
- Length 4 cm
- Top speed 1 km/h
- Lifespan 3 years
| Scientific name | Latrodectus mactans |
|---|---|
| Diet | Carnivore (insects) |
| Habitat | Dark corners, woodpiles, and outbuildings |
| Lifespan | Around 3 years in the wild (varies by population and captivity). |
| Weight | About 0.001 kg typical adult mass (sex and region vary). |
| Top speed | Up to roughly 1 km/h when moving at speed. |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Arthropoda |
| Class | Arachnida |
| Order | Araneae |
| Family | Theridiidae |
| Genus | Latrodectus |
Where it lives
The black widow (Latrodectus mactans) is native to Warm regions of the United States, especially the South, and into Mexico. — recorded across North America in this guide’s range summary.
For occurrence records, see GBIF species search and sources below.
How big is a black widow?
An adult black widow measures 4 cm long — about 2% of the height of an average adult person (1.73 m) — and weighs around 1 g, a small fraction of an average adult’s body weight (70 kg).
Length vs an average adult’s height (to scale)
What is a group of black widows called?
Group name (collective noun)
A group of Black Widows is called a cluster.
Baby name
A baby Black Widow is called a spiderling.
Explore more animal collective nouns and baby animal names .
Hourglass in a tangled web
Mature females are glossy black with the diagnostic red hourglass; males are smaller and lighter-marked. Webs are messy, three-dimensional snares in sheltered voids rather than neat orbs.
Insects in the tangle
Prey includes beetles, cockroaches, flies, and other arthropods that blunder into the web. The spider wraps victims in silk before delivering a venomous bite.
Warm US outbuildings
Dark corners, woodpiles, utility cupboards, and outbuildings across warm parts of the United States, especially the South, and into Mexico. Across its range it is tied to dark corners, woodpiles, and outbuildings, and field accounts emphasise this species’ distinctive ecology rather than generic habitat labels.
Medical significance, not aggression
Least Concern and not aggressive; bites usually occur when a spider is pressed against skin. Latrotoxin can cause severe pain and systemic symptoms — seek medical care, especially for children and older adults.
Explore the Black Widow
Related Invertebrates
Range & geography
Conservation status of the Black Widow
The black widow (Latrodectus mactans) is listed as Least Concern on the IUCN Red List. Least Concern (LC) is the IUCN's lowest-risk category, assigned to widespread, abundant species that have been evaluated and found not to be threatened. It does not mean a species faces no pressures — only that it is not currently at risk of extinction.
The black widow (Latrodectus mactans) is assessed on the IUCN Red List. Look up on the IUCN Red List .
Frequently asked questions about the Black Widow
What does a black widow bite feel like?
Often sharp pain at the site followed by muscle cramps and systemic symptoms; get medical advice promptly.
Do male black widows have an hourglass?
Males are smaller with different markings; the classic red hourglass is typical of mature females.
Are black widows aggressive?
No — they bite defensively when pinned or threatened, not when merely nearby.
Where do black widows build webs?
Sheltered, dark places — woodpiles, sheds, crawl spaces, and cluttered outdoor corners.
Is black widow venom always fatal?
No. Modern medical care makes deaths rare in healthy adults, though bites are serious and need treatment.
What is a group of black widows called?
A group of Black Widows is called a cluster.
What is a baby black widow called?
A baby Black Widow is called a spiderling.
Sources & references
This guide is compiled and reviewed against established zoological and conservation references. Key sources for the Black Widow:
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IUCN Red List of Threatened Species
Conservation status (Least Concern) reflects the IUCN Red List category for Latrodectus mactans.
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iNaturalist — observations & photos
Search citizen-science observations and community IDs for Latrodectus mactans. Useful for range checks and recent sightings — not a substitute for formal Red List status.
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GBIF — occurrence data
Global Biodiversity Information Facility species search for Latrodectus mactans. Explore published occurrence records used in range research.
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How we research, source, review, and update every guide for accuracy.
