Agelenopsis, American grass spiders, are a genus of spiders that can be found around the world and in every US state. They are some of the fastest spiders in the United States and can be fun just to watch if you can trigger the web right.
Using a long piece of a weed or grass, try tickling the web as a bug would, if it was struggling across the web. If you do it right, the Grass Spider will run out with lightning speed, looking for a meal.
Then again, if you don’t mind seeing it, you can always throw a bug in its web.
Quick Overview: Agelenopsis – American Grass Spider
Medically significant: No
Body size: 3/4 inch (19 mm)
Main colors: brown, black
Range: Throughout the United States
Web: Funnel-shaped web
Agelenopsis Description
The abdomen is oblong, with long spinnerets at the end. Most species of the American Grass Spider have a pattern of stripes running from front to back. On the abdomen, there are often two white stripes, which are broken into many sections. The Cephalothorax on the other hand, has the lighter stripe running down the middle, dividing two dark stripes.
The grass spider is often confused with some similar looking species of the wolf spider or the American Nursery web spider. In the Pacific Northwest, the grass spider’s distribution overlaps with the related hobo spider (Eratigena agrestis) and the giant house spider (Eratigena atrica). Both of these spiders are also part of the funnel-weaver family (Agelenidae) and have a similar appearance to the grass spider. The best way to distingiush the grass spider from these species are the clear three lighter lines that run along the cephalothorax (head) of the grass spider. Hobo spiders and giant house spiders don’t have these longitudinal lines but other, less-distinctive markings.
Eyes
Grass spiders have eight eyes. The eight eyes are all similar-sized and form an oval shape. You can see a closeup photo of the grass spider eyes below:
Size
The bodies will grow to 3/4” (19 mm) from front to back, and approximately 1 ½” (38 mm) including the legs.
Web
They always spin their webs horizontally, creating a thick floor, which will feed into a funnel at one end. The spider hides in the funnel section, waiting for its next meal to crawl upon its web. However, the webs are not the sticky kind, which are used to trap prey. Instead, they trigger vibrations on the web, which the spider feels. The Grass Spider then uses its speed to charge and attack its prey.
Grass spider bites
The Grass Spider is considered quite harmless to humans. They stay in their webs and do not venture out unless forced to do so. A bite can cause some local swelling, redness and itchiness but is not dangerous.
Agelenopsis Scientific Classification
- Kingdom: Animalia
- Phylum: Arthropoda
- Subphylum: Chelicerata
- Class: Arachnida
- Order: Araneae
- Infraorder: Araneomorphae
- Family: Agelenidae
- Genus: Agelenopsis
Other common names
The Grass Spider is also known as the American funnel-web spider or funnel weaver. It is not to be confused with the Funnel Web Spider, which is a very dangerous spider in Australia. To limit confusion, we strictly stick to the name American grass spider or grass spider.
Distribution of the American grass spider in the USA
Various species of the American grass spider can be found throughout the United States – Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming
Grass spider photos
Here are some more photos of grass spiders that have been submitted by our readers:
A great closeup shot showing the eye pattern of a grass spider (Agelenopsis) . Found in New Jersey by Rich. 
Exosceleton of a grass spider- Submitted by Jaye Bird 
An American grass spider found by Kalie. 
A gravid grass spider found by Teresa in Sioux Falls, South Dakota 
A slender grass spider with long spinnerets. Found by Jess. 
Grass spiders are often confused with similar-looking wolf spiders. This grass spider was found by Lisa in Withee, Wisconsin. 
Agelenopsis spider found by Gabriel in October 2020.
Hey I found of the grass land spiders and I just want to know if they make good pets
Hey Jerry, thanks for getting in touch! Yes, you can absolutely keep a grass spider as a pet. Grass spiders are funnel weavers and create funnel-shaped webs. Make sure to add some twigs and leaves in one area/corner of the enclosure where it can set up its web.
Here is some more information:
https://www.wikihow.com/Keep-Grass-Spiders
Is this a grass spider? Found in northern MN. I have a lot of these in my house. The orange-ish oval on its back is making me question it. It’s approx: 1/2 inch
Hello Reef, thanks for getting in touch. This is a wolf spider, not a grass spider. You can read more information about them here: https://usaspiders.com/lycosidae-wolf-spider/
They are also harmless.
Found this spider just inside my back door? I didn’t see any photos on your site that look like this.
Hi John, thanks for the photo. This is some type of funnel-web spider of the family Agelenopsis. It could be Agelenopsis naevia but it’s hard to make an ID off the picture alone. It would help if you could mention the location where you found the spider.
Regardless of the exact genus or species, Agelenopsis spiders are not medically significant. You can read our overview of the similar and closely related American grass spider here: https://usaspiders.com/agelenopsis-american-grass-spider/
I’ve seen a few of these around my house in Indiana. Not quite sure what it is.
Hello Kaymen, this is a wolf spider (Lycosidae), not a grass spider: https://usaspiders.com/lycosidae-wolf-spider/
O-0 big ol’ quarter sized spider found in northern utah, no web. Primarily brown and gray(?)
Hello Nessa, this is some type of funnel-web spider of the spider family Agelenidae. They are not medically significant. It might be a grass spider or a close relative. Here is more information about it: https://usaspiders.com/agelenopsis-american-grass-spider/
Hi! Nashville Indiana here…
This medium sized guy came to visit me in my garden tonight. Your thoughts on who he is is greatly appreciated!
Hi Theresa, thanks for getting in touch! This is a wolf spider, not a grass spider. Wolf spiders are also not medically significant: https://usaspiders.com/lycosidae-wolf-spider/
Hi, I found a spider who looked exactly like the one used as the main example for American grass spiders before clicking the the “more” link in my kitchen sink tonight. It was definitely NOT the size of a quarter – more like a half dollar, and probably a bit larger, still. As I had no idea what it was and my three year old was at my side, my only concern was making sure I secured my home but it didn’t seem to be bothered by the pot of water potted on it and it couldn’t scale the sink basin to get out. Could it have been a harmless grass spider? Do they get that big?
Hello Denise, yes, grass spiders can get that big. It might have also been a giant house spider (Eratigena atrica) – they look somewhat similar: https://usaspiders.com/eratigena-atrica-giant-house-spider/
It depends on your location. None of the large brown spiders that look similar to grass spiders in the U.S. are medically significant. The only medically significant brown spider is the brown recluse which is not that big and looks different.
What is this spider and is it a concern since I have 2 small dogs and a child?
Hello Mike, thanks for getting in touch! This spider is not medically significant for humans or dogs. It’s a grass spider: https://usaspiders.com/agelenopsis-american-grass-spider/
Found this in a pair of shoes I just purchased. Any idea what it is? Dangerous?
Hello Steven, thanks for getting in touch. This is an American grass spider (Agelenopsis sp.). It’s not a medically significant spider: https://usaspiders.com/agelenopsis-american-grass-spider/
I live in New Jersey, and I saw these two spiders this evening by the garage. I’ve never seen this kind of web before. I took another photo from the side to show you what their bodies look like. What kind of spiders are they?
Hello Barbara, it’s hard to ID them just off their webs – they could be some type of cobweb spiders or even orb weavers with the web on the left belonging to a different species. Can you upload the picture of the spider itself to the reply here? That will help with the identification.
Hellllpp! I hate spiders and this is the second one I’ve found I my apartment in the last week!
Found this spider by my door in Shenandoah county Virginia, overall it was larger than a quarter.
Hello Kirk, thanks for getting in touch! This is a gravid female funnel web spider – most likely a grass spider (Agelenopsis sp.). It’s not a medically significant spider. They spin funnel-shaped webs in corners and catch smaller insects: https://usaspiders.com/agelenopsis-american-grass-spider/