Spiders
Spiders in Michigan, the common ones and the two worth knowing
Michigan has about 500 native kinds of spiders, MSU said in 2018, and only a few matter for your health. Here's which ones people in Southeast Michigan post most, where they live around your house, and the two worth knowing: the northern black widow and the rare brown recluse.
By John Stone, veteran technician / sales managerLicensed and insured in MichiganPublished
Summary
The short answer
There are about 500 native kinds of spiders in Michigan, by MSU's 2018 count. The ones your neighbors post most are jumping spiders and orb weavers. MSU says only three native spiders are medically important. The northern black widow appears more common on the west side of the Lower Peninsula. Brown recluses aren't native and are rare, found in 11 counties.
Spiders very rarely bite people, and they eat a lot of insects. The two you should know by sight are the northern black widow and the brown recluse. Worried about a bite? Michigan's poison center answers 1-800-222-1222, day and night.
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The short version, read aloud. Read by a synthetic voice, not one of our technicians.
In Southeast Michigan, the spiders people post most are jumping spiders, orb weavers, and big nursery web and fishing spiders. Here's where each one lives, and the two you should know by sight.
Which spiders in Michigan will you actually see?
Mostly jumping spiders and orb weavers. We counted every checked spider sighting on iNaturalist, where people post bug photos and others confirm the ID. If you live in Washtenaw, Wayne, Oakland, Livingston, Monroe, Jackson or Lenawee County, that's your area. We found 11,058 sightings of 190 species.
As you can see below, the bold jumping spider is way out front. Three of the top eight are jumping spiders. Sightings peak in September (2,304) and August (2,053).
The spiders people post most in Southeast Michigan
Research-grade iNaturalist sightings of the top 8 species in Washtenaw, Wayne, Oakland, Livingston, Monroe, Jackson and Lenawee counties, all years: 11,058 sightings of 190 species in all. Our count, pulled October 13, 2026. These are photos people chose to post, mostly outdoors, so they follow where people look, not how many spiders there are. Jumping spiders are the darker bars.
Where do they live around your house?
Most live outside, and a couple of kinds can live in your basement. Hunters like wolf spiders live outdoors. They may wander into your house by accident, especially in fall, the University of Minnesota says. They don't survive well inside and usually don't breed there. Our house spiders post covers why fall feels like spider season, and the webs in your corners.
The table sums up each one, going by the University of Minnesota, MSU and the Burke Museum.
| Spider | Where you see it | Size or field mark | Bite risk, in plain words |
|---|---|---|---|
| Yellow garden spider | Usually in the middle of a big round web, late summer | Black and yellow | Not dangerous. Leave it alone. |
| Wolf spider | Outdoors; may wander in by accident, especially in fall | 1/4 to 1 inch, dark brown, a bit hairy | Not aggressive, just big and fast |
| Fishing spider | Near ponds, swamps and slow streams; some turn up far from water | About 1 inch; some span up to 4 inches with legs | Rare. Spiders very rarely bite people. |
| Cellar spider (daddy longlegs) | Loose webs in basement and crawlspace corners | 1/4 to 1/3 inch, pale gray to light tan, long thin legs | No super venom. That story's a myth. |
| American house spider | Loose, tangled webs in basements and crawlspaces | Over 1/4 inch, gray to brown, chevron marks on the abdomen | Rare. Spiders very rarely bite people. |
| Northern black widow | Stumps, hollow logs, brush piles, shed and crawlspace corners | Red hourglass underneath, split in the middle | Medically important, but timid. Bites are infrequent. |
Which Michigan spiders are dangerous?
Just a few. In 2018, MSU said only three native spiders here are medically important. They're the northern black widow, the yellow sac spider and, to a lesser degree, the northern cobweb spider. The brown recluse isn't native, so it's not on that list. Think you've got a yellow sac spider? Our house spiders post covers it.
The CDC lists the black widow and the brown recluse as venomous spiders found in the US. Those are the two you should know by sight.
Every Michigan spider uses venom on its prey, and most will try to bite if threatened, MSU says. But spiders very rarely bite people. The CDC says they're usually not aggressive. Most bites happen when a spider gets trapped or touched. So don't grab one with your bare hand.
Where do black widows live in Michigan?
Most sightings come from the west side of the Lower Peninsula and up north. MSU says the northern black widow appears to be more common in the western Lower Peninsula. Our own count lines up: 117 checked iNaturalist sightings in 32 counties. If you live in Southeast Michigan, only one of those was in your corner of the state, in Wayne County.
At least one checked northern black widow sighting
Outside, MSU says, they live in old stumps, hollow logs, brush piles and old animal burrows. They also hide under fallen fence posts and in shed and crawlspace corners. Look before you reach in there. If you get a look at one, the red hourglass underneath is split in the middle. There's a row of red spots down its back, too.
Good news: bites are infrequent, MSU says, because the spider is very timid and would rather run. US poison centers logged 9,872 black widow cases with symptoms from 2000 to 2008, a 2011 study found. 65% were minor, and none were fatal. Cases peaked in September.
If a spider bites
- Stay calm. If it's safe, figure out which spider got you.
- Wash it. Use soap and water on the bite.
- Cool it. Put a cold, wet cloth or a cloth with ice on it, and raise it if you can.
- Leave the venom. Don't try to get it out. Get medical care, the CDC says.
You can call Michigan's poison center at 1-800-222-1222, free, 24/7. Call 911 right away if someone passes out, has trouble breathing or has a seizure.
Are there brown recluses in Michigan?
A few, but they're rare. Michigan isn't in their native range. Still, MSU says there are a few small, isolated groups here. People carried them in, often hiding in papers and boxes.
MSU updated its list in October 2026. Brown recluses have now been found in 11 counties. Allegan, in west Michigan, is the new one. If you're in Washtenaw, Wayne, Oakland, Livingston or Lenawee, your county is on it.
Brown recluse records confirmed by MSU
Don't panic, though. Over about 14 months, people sent MSU about 700 photos of spiders they thought were recluses. Only seven were, MSU reported in 2018. It says most Michiganders will never come within half a mile of one. So if you're worried about a big brown spider, odds are it's not a recluse. The dark fishing spider and the nursery web spider fool people most. Our brown recluse post shows how to tell them apart.
Is it really a spider bite?
Often not. At one California ER, 182 patients blamed a spider bite. Doctors diagnosed only 7 of them with a real spider bite, a 2011 study found. They diagnosed 156 with infections. So if you woke up with a sore and blamed a spider, it could be something else.
And don't go by two little marks. Real fang punctures are hardly ever visible, the Burke Museum says. So if a sore keeps getting worse or you feel sick, get it checked.
When should you call us?
You don't need us for one spider. Spiders eat a lot of insects. And it's not practical to make your home spider-free, the University of Minnesota says.
Call us if the webs keep coming back on your eaves and windows, or you keep finding big ones in the basement. Our spider control page shows what a visit covers. Spiders are part of Honorable Shield, too.
Webs on the eaves and spiders in the basement?
We clear webs from the eaves and windows, treat where spiders hide and hunt, and cut down the insects that feed them. Spiders are covered by Honorable Shield, and quotes are free.
Common questions
What's the biggest spider in Michigan?
Probably a fishing spider. The University of Minnesota says fishing spiders are the biggest spiders in the Upper Midwest. They're about an inch long, and some span up to 4 inches with their legs. Here, the dark fishing spider is one of the two spiders people most often mistake for a brown recluse, MSU says.
Are daddy longlegs the most venomous spiders?
No, that's a myth, the Burke Museum says. "Daddy longlegs" can mean a harvestman, a crane fly or a cellar spider. None of them has super-powerful venom. They have no venom, or very weak venom.
Do you swallow spiders in your sleep?
There's no evidence of it, the Burke Museum says: no specimens, no eyewitness accounts, nothing. So you can cross that one off your list of worries.
How many kinds of spiders live in Michigan?
About 500 native kinds, MSU said in 2018. In seven Southeast Michigan counties, people have posted checked iNaturalist photos of 190 species. The bold jumping spider is the one they post most.
About this page
John wrote this. The facts come from the sources below, checked on October 13, 2026. The sighting numbers and the black widow map are our own iNaturalist count, so they show where people look, not how many spiders there are. We're not doctors, so call yours about a bite that worries you. See something wrong? Tell us and we'll fix it.
Sources
- Michigan State University, MSU Plant & Pest Diagnostics, Brown Recluse (2025, updated October 2026)
- Michigan State University Extension, Don't panic over brown recluse spiders in Michigan (2018)
- Michigan State University, MSU Plant & Pest Diagnostics, Northern Black Widow Spider (Latrodectus variolus)
- Michigan Poison & Drug Information Center, Wayne State University School of Medicine, Call Center
- Centers for Disease Control and Prevention, NIOSH, Venomous Spiders at Work (2026)
- Suchard, "Spider bite" lesions are usually diagnosed as skin and soft-tissue infections, Journal of Emergency Medicine (2011)
- Monte, Bucher-Bartelson and Heard, A US perspective of symptomatic Latrodectus spp. envenomation and treatment: a National Poison Data System review, Annals of Pharmacotherapy (2011)
- University of Minnesota Extension, Spiders
- Burke Museum of Natural History and Culture, University of Washington, Spider Myths
- iNaturalist, research-grade spider observations in Washtenaw, Wayne, Oakland, Livingston, Monroe, Jackson and Lenawee counties, and northern black widow observations in Michigan (our count, pulled 2026-10-13)
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