Black Widow Spiders
Latrodectus species
DangerousWhat it is
A medically significant cobweb spider, typically glossy dark in color; adult females often have a red hourglass marking beneath the abdomen. They favor protected, undisturbed areas and bites can require medical attention.
How to recognize it
- The female is glossy black with a round abdomen, about 1/2 inch long without legs
- A red or orange hourglass on the underside of the abdomen, sometimes broken into two triangles
- Young spiders are brown or cream with stripes and darken as they grow
- Messy, strong, tangled web close to the ground in dark, sheltered spots
Where you will find it
Woodpiles, sheds, garages, meter boxes, under outdoor furniture, and in basements and crawl spaces.
Found in much of the US, and most common in warmer regions.
Why it matters
The bite can be medically significant. Never handle one, and get medical care after a bite.
Look-alikes
- False widow: Brown to purplish, with no red hourglass. Bites are generally milder.
- Common house spiders (cobweb spiders): Brown or gray, with no hourglass marking.
What to do
- Clear clutter and woodpiles away from the house.
- Don't handle one. Take a photo from a safe distance and call a professional to remove it.
When to call a professional
- You find one inside your home or near where children play.
- You see more than one, or egg sacs.
Questions
Is a black widow bite deadly?
Deaths are rare. Bites can cause severe pain, muscle cramps, and nausea, and need medical care, especially for children, older adults, or anyone with health problems.
What should I do if I'm bitten?
Wash the area, apply a cold pack, and get medical care promptly. If you can do it safely, bring the spider or a photo.
Do black widows come inside?
They prefer sheltered spots such as garages, basements, and sheds, but can end up in homes.
Related pests
Cellar Spiders
Long-legged, delicate spiders that build loose webs in basements, crawlspaces, garages, and other quiet areas. They are generally harmless and feed on small insects and other spiders.
Read more →Daddy Longlegs
A common name often used for harvestmen, which are arachnids with a single rounded body and very long legs. They do not have venom glands like spiders and are generally harmless scavengers or predators.
Read more →Hobo Spiders
Funnel-web spiders that build sheet-like webs with a retreat, often near ground level. They are generally shy and bites are uncommon; modern evidence does not support many older claims of severe necrotic injury.
Read more →Sac Spiders
Hunting spiders that rest in small silk sacs rather than permanent capture webs. They may wander indoors on walls and ceilings and can bite if trapped against the skin, though serious reactions are uncommon.
Read more →This page is general information, not a diagnosis. Pests vary by region and situation, and an on-site inspection is the reliable way to know what you have.