| Scientific name | Latrodectus mactans |
|---|---|
| Group | Spiders |
| Size | 3–13 mm (up to about 0.51 in) |
| Colors | Black and Red |
| Legs | 8 legs |
| Wings | No (as usually seen) |
| Where found | Basement or garage, Yard or patio and Woods or trails |
| Most active | Spring, Summer, Fall and Winter |
| Bites | Yes |
| Stings | No |
| Risk level | Health risk |
How to identify it
The black widow spider is a small member of the spiders group. Eight legs, two body sections and silk-spinning organs at the rear. Check for these three features:
- Glossy black, globe-shaped abdomen
- Red or orange hourglass marking underneath
- Irregular, strong tangled web close to the ground
About this bug
A shiny black spider with a red hourglass on the underside of its round abdomen. It builds messy, tangled webs in woodpiles, sheds, meter boxes and outdoor furniture.
You'll usually find black widow spiders in basements and garages, in yards and on patios and in woods and along trails. They are most active in spring, summer, fall and winter.
Is it dangerous?
Females have venom that can cause severe muscle pain and cramps; seek medical care after a bite.
Our rating: Health risk, meaning it can cause medically significant bites, stings or disease.
Call 911 right away if someone has trouble breathing, swelling of the face or throat, dizziness or a racing heartbeat after a bite or sting.
When you'll see black widow spiders
Black Widow Spiders are most active in spring, summer, fall and winter. In spring, overwintering adults become active and many species lay their first eggs. Summer heat speeds up development, so populations can grow quickly. In fall, many bugs look for shelter, and some move toward or into buildings. In winter, activity continues mainly indoors in heated spaces.
Typical places to check: basement or garage, yard or patio and woods or trails.
About spiders
The black widow spider is one of the spiders. Spiders have eight legs, two main body sections and no antennae. Almost all spiders have venom to subdue prey, but only a few have venom that matters to people. Many build webs, while others, such as wolf spiders and jumping spiders, hunt on foot.
Spiders go where their food is. A home with lots of spiders usually has plenty of other insects, so general pest control reduces spiders too.
What to do about it
- Wear gloves when moving firewood, boxes and outdoor items
- Clear clutter from garages, sheds and crawl spaces
- Remove webs and egg sacs with a vacuum or long tool
Read the full guide: how to get rid of black widow spiders.
Bugs that look similar
Size: Southern House Spiders are larger, reaching 19 mm, while black widow spiders top out around 13 mm.
Size: Black Widow Spiders are larger, reaching 13 mm, while common house spiders top out around 8 mm.
Size: Bold Jumping Spiders are larger, reaching 15 mm, while black widow spiders top out around 13 mm.
Frequently asked questions
What does a black widow spider look like?
Glossy black, globe-shaped abdomen. Adults measure 3–13 mm (up to about 0.51 in).
Does the black widow spider bite or sting?
It can bite. It does not sting. Females have venom that can cause severe muscle pain and cramps; seek medical care after a bite.
Where do black widow spiders live?
Black Widow Spiders live in basements and garages, in yards and on patios and in woods and along trails.
When are black widow spiders most active?
Mostly in spring, summer, fall and winter.