Agelenopsis – American Grass Spider

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.

Photo of the size of an american grass spider
Photography by: K. J. Ester – Macomb Mi.

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.


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:

Agelenopsis grass spider eyes closeup high resolution
The eye pattern and fangs of a grass spider. Photo used with persmission from Chase Noble


The bodies will grow to 3/4” (19 mm) from front to back, and approximately 1 ½” (38 mm) including the legs.

Agelenopsis grass spider closeup high resolution body top view
An american grass spider. Photo used with permission from Chase Noble.


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 in funnel web agelenopsis
A grass spider in a funnel web photographed by Roxie in Alabama

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 spider in the USA
Photography by: Paige Borgeson – Muskegon, Mi.

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

Agelenopsis Grass Spider Range

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:

Agelenopsis – American Grass Spider

23 thoughts on “Agelenopsis – American Grass Spider

    1. 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:

  1. 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

  2. Found this spider just inside my back door? I didn’t see any photos on your site that look like this.

    1. 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:

  3. O-0 big ol’ quarter sized spider found in northern utah, no web. Primarily brown and gray(?)

  4. 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!

  5. 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?

    1. Hello Denise, yes, grass spiders can get that big. It might have also been a giant house spider (Eratigena atrica) – they look somewhat similar:
      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.

  6. 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?

    1. 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.

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