The Cat Face Spider (Araneus gemmoides) is a fascinating species of spider belonging to the orb weaver family Araneidae.
Commonly found in the western parts of North America, these spiders are easily identifiable by their unique appearance, which features two “horns” on the sides of their abdomen, resembling a cat’s face.
As orb weavers, Cat Face Spiders are known for constructing intricate, circular webs to catch their prey.
Despite their somewhat intimidating appearance, Cat Face Spiders are actually quite harmless to humans.
In fact, they provide a valuable service by helping control insect populations in gardens and around homes.
Adult female Cat Face Spiders are generally larger than the males, and their color can range from a light yellow-brown to a dark reddish-brown.
Males are much smaller and typically have a more slender body shape, making them less often noticed.
Cat Faced Spider Identification
Cat faced spiders are orb-weaver spiders with unique features that resemble a cat’s face.
Their scientific name is Araneus gemmoides and they are commonly found throughout North America.
Features to note:
- Cat ears: The distinct “cat ears” are actually bumps or dimples on the abdomen.
- Shape: The overall shape of the spider is round and smooth.
Color and Patterns
The coloration of cat faced spiders varies, but there are certain patterns that can aid in identification:
- Colors: They can be found in shades of brown, yellow, and even a dark form1.
- Patterns: The abdomen often features lighter, mottled patterns, while the presence of cat ears gives them their name.
Size and Sexual Dimorphism
Cat faced spiders exhibit sexual dimorphism, meaning that males and females differ in size and appearance2.
- Females: The large full-grown females vary from about 13mm to 25mm long and 4.5-5.5 mm wide1.
- Males: Males are significantly smaller in size (between 5mm and 8mm)1.
Here’s a comparison with the brown recluse spider
|Spider Species||Size||Eye Pattern|
|Cat Faced Spider||5-7 mm (F)||8 eyes, 2 rows of 4|
|Brown Recluse||Varies||6 eyes, 3 pairs|
By knowing its physical appearance, color patterns, and size differences between males and females, it becomes easier to identify a cat faced spider in the wild.
Habitat and Distribution
Their range spans multiple states, including Arizona, Colorado, Michigan, California, and Missouri.
These spiders can also be found in parts of British Columbia.
Preferred Living Spaces
The preferred living spaces for Cat Faced Spiders include:
- Animal burrows: They often take shelter in animal burrows to stay protected.
- Garden vegetation: These spiders reside among plants, bushes, and trees, as they provide coverage and support for their webs.
Migration and Population
Cat Faced Spiders experience population growth during late summer, when mating occurs.
Males move about in search of receptive females, while females store sperm for later egg fertilization.
After laying eggs, the females die, making late summer the peak of their population.
Diet and Hunting Techniques
The Cat Faced Spider primarily feeds on a variety of garden insects, including:
- Flies: They enjoy feeding on house flies and other flying insects.
- Mosquitoes: These spiders can help control mosquito populations in your garden.
- Other small insects: These can vary depending on the spider’s habitat.
Cat Faced Spiders employ both of the below strategies to catch their prey:
- Web Construction: They build orb-shaped webs that aid in trapping various flying insects.
- Ambush: They wait patiently for an unsuspecting insect to fly into their web.
A comparison of Cat Faced Spider’s diet and hunting techniques with those of other common garden spiders:
|Spider Type||Diet||Hunting Techniques|
|Cat Faced Spider||Flies, mosquitoes, small insects||Web construction, ambush|
|Orb Weaver||Flies, mosquitoes, moths, beetles||Web construction|
|Jumping Spider||Flies, small insects, other spiders||Stalking, jumping|
The Cat Faced Spider is a beneficial addition to your garden, as they feed on common pests and help maintain a balanced ecosystem.
Behavior and Life Cycle
Mating and Reproduction
Mating in this species occurs in late summer, as smaller males actively search for receptive females.
Once mated, females store the sperm until they lay their eggs.
Egg Sacs and Spiderlings
After mating, the female Cat Faced Spider produces a silk egg sac containing her eggs.
The egg sacs are often deposited in a safe location near their web, providing protection for the soon-to-be spiderlings.
Once hatched, the young spiders leave the egg sac and disperse.
Egg Sac Features:
- Silk-based structure
- Protection for eggs
- Located near the web
Lifespan and Growth
These spiders grow and develop throughout the spring, reaching maturity by late summer.
As members of the class Arachnida, the Cat Faced Spider undergoes a series of molts, shedding its exoskeleton as it outgrows it.
However, their exact lifespan varies depending on factors such as predation and environmental conditions.
Being nocturnal spiders, Cat Faced Spiders are most active during the night, when they build their orb-like webs to capture prey, such as flies and other small insects.
During the day, these spiders remain relatively inactive, hiding in crevices or near their webs.
The Cat Faced Spider is generally harmless to humans and can be found living near or on buildings.
Cat Faced Spider and Its Relationship with Other Species
Predators and Threats
The Cat Faced Spider (Araneus gemmoides) is an orb-weaver spider commonly found in gardens and around homes across the USA.
This arachnid encounters various predators in its natural habitat, such as:
- Wasps: Some wasp species, particularly mud daubers, actively hunt spiders. They paralyze them and store them in their nests as a food source for their larvae.
- Animals: Threats also include animals that inadvertently stumble upon and crush spiderlings in their burrows.
Role in the Ecosystem
As a member of the arachnid family, the Cat Faced Spider plays a significant role in maintaining the balance of their ecosystem. Some of their contributions include:
- Preying on insects: By feeding on various insects, they help control pest populations in gardens and other habitats.
- Providing food for other species: The spiders themselves are a source of food for their natural predators, such as wasps and some larger animals.
Interaction with Humans and Pets
Cat Faced Spiders generally do not pose a significant threat to humans or pets, as they are not known to be highly venomous.
However, they can bite when provoked or threatened. In most cases, a bite from a Cat Faced Spider will cause minor pain or irritation and is comparable to that of a bee sting. It’s essential to:
- Exercise caution: When working in gardens or areas inhabited by these spiders, be mindful of their presence to avoid accidental contact.
- Keep pets supervised: Monitor pets in outdoor spaces where the spiders might be present to prevent them from disturbing the arachnids.
The Cat Faced Spider, a unique orb-weaving spider, is a captivating creature native to North America.
Its distinguishing “cat ears” on the abdomen, beneficial pest control role in gardens, and harmless nature towards humans make it an intriguing species.
Although its interaction with other spiders and exact range are areas for further exploration, understanding its habits, appearance, and contribution to ecosystem balance is crucial for both arachnophiles and garden enthusiasts.
Through continued research, we can uncover more about this spider and its place in the entomological world.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Cat Faced Spider
Subject: Orange Spider with horns on back
Location: Ojai, California
November 5, 2012 2:57 pm
Hi Mr. Bugman!
I was wondering if you can identify this orange spider. I searched for orange spiders on your site but did not see one that matches.
It’s an orb weaver since it’s made a magnificent round web. The web is between 2 bushes about 2-1/2 feet in diameter.
The spider’s body is about the size of a quarter. Lets spread out it would probably be the size of a half dollar.
I’m particularly interested because I’ve never seen a spider with horn protrusions on its back.
We are in Ojai, California, a tiny valley town just inland from the Southern California coast. We get a lot of bugs here, and your site has helped us so much in identifying them.
Thanks so much!
Signature: Spider Admirer
Dear Spider Admirer,
We believe this is a Cat Faced Spider, Araneus gemmoides. According to BugGuide, they can be identified by: “The fine white line crossed by two shallow white Vs on the front of the abdomen. This is a classic characteristic of Araneus gemmoides.
How strong these lines are, and, to a certain extent, their shape, is variable from one individual to another.” Nothing is mentioned about the “horns” on BugGuide, but most photos appear to have them. BugEric has an excellent page on the Cat Faced Spider where it is noted:
“Araneus gemmoides is one of the angulate orb weavers that often sport a pair of conical humps near the front of the top of the abdomen. These “horns” mark the “ears” of the cat face, with variable markings on the abdomen reinforcing the feline moniker.”
Wow, Daniel, thank you so much!! That is so great! I happen to be a huge cat lover, so really like the idea of the Cat Faced Spider taking up residence nearby. I really appreciate your finding the name.
Thanks for building such a great site! My son LOVES bugs and has learned so much from you!
Our pleasure Bonnie. When we began this column in a small photocopied “zine” in the late 1990s, it was because we were asked to contribute a column to American Homebody by dear friend and collaborator Lisa Anne Auerbach.
We chose What’s That Bug? because of our own childhood love of insects and we maintained at a very early stage that everyone really did want to know “What’s That Bug?” upon encountering some strange and unfamiliar creature in the home or garden.
Upon taking the project online, that really did turn out to be an accurate prediction.
Letter 2 – Cat Faced Spider
I was really hoping to find my mystery spider on your page. Since it was not there, Here it is! Please help. This one is really ugly (beautiful?) — scary looking (since I have 3 small children). Thus, I felt compelled to put it to rest after taking the photos.
I have lived in Salt Lake, Utah area for 7 years and have never once seen anything even resembling this spider. Further questions are: I’m assuming since I have seen one, and it appeared mature (about the size of a walnut when curled up, the butt (abdomen, thorax?) is about the size of a garbanzo bean.) there must be more around.
I have lived in this house for 7 months and this is the first I have seen of this type of spider. It was outdoors. Should I expect to see more of them or is this a unique situation. Does it live underground? In trees? Fields? Anyways. I guess any information you could give me on it would be helpful and once identified I could do some research on my own.
IT appears to RESEMBLE a verrucosa type. But the legs appear much “healthier” in size. After reading everything on your site I feel bad about “getting rid of” it. I was in a hurry and didn’t want it to get away if it was dangerous for my children. Please forgive me.
Salt Lake City, Utah
First, I must appologize for the lengthy delay. Sometimes we can identify something quickly and other times a very circuitous route brings us to an answer.
Just yesterday, I got a letter from young Nicholas inquiring about a Catspider. I had never heard of it. His dad wrote back thanking me and providing a link that lead to the identification of your spider, Araneas gemmoides, the Cat Faced Spider. Here is Nicholas’ dad’s letter:
(01/20/2005) Dear Bugman, What my son is referring to is a Cat Spider, aka Cat-face Spider, and what this site is calling Araneus gemmoides. There are never very many, but we occasionally get one living on our porch.
They create big, beautiful and strong orb webs. As a kid, we called the one on our porch a “pet”. I seem to remember hundreds of baby cat spiders hatching all at once. We will be sure to send you a picture if we see another one this coming summer.
Thank you for taking the time to answer my son’s questions. He’s a bit of a young spider & bug fanatic, and always has at least one tank (usually more) with a spider inside – he even kept a black widow for about 3 weeks over the summer, which was both fascinating and scary for us as parents.
Letter 3 – Cat Faced Orbweaver
Subject: Just curious
August 9, 2015 9:21 pm
A spider found in Colorado that is especially creepy – trying to figure out what kind of spider it is and what its attributes are
Signature: Amity Wagner
This is a harmless Orbweaver in the genus Araneus, and we believe, because of the projecting bumps on the abdomen, that it is a Cat Faced Orbweaver, Araneus gemmoides.
Letter 4 – Cat-Faced Spider
Subject: What mind of spider is this?
Location: San Francisco/ Bay Area
October 21, 2015 7:58 pm
Found this spider in our backyard in Northern California.
Because of the two prominent bumps on its abdomen, we believe your Orbweaver is a Cat-Faced Spider, , and you can read more about the species on BugGuide.