Holmes Lawn & Pest Blog

How To Identity The Most Common Utah Spiders

Jumping Spider Cute face

The dangers of spiders are well documented throughout history. Due to their creepy-crawly nature and the dangers posed by some of the more venomous species, spiders have become an international sign of horror. The good news? Not all venomous spiders have the ability, or even the desire, to seriously harm you. The bad news? Certain spiders can and will cause injuries if they feel threatened. Holmes Lawn & Pest wants to make sure you know what to watch out for when it comes to dangerous spiders on your property. This post is designed to give you a better idea of which spiders are dangerous and how you can identify them. 

Dangerous Spider Species In Utah

The most feared of all venomous spiders in Utah, and in the United Stated as a whole, are black widow spiders. Black widow spiders are unquestionably the most dangerous spiders you could encounter in Utah. Depending on the specific species of black widow spider, the markings on their bodies can be unpredictable. The black widow spiders in Utah are likely to be western or southern black widows. The males are considerably smaller, they are usually a brown to greenish color, and their bites do not cause serious or life threatening injuries. The female black widow spider has the shiny black body and red hourglass shape under its plump abdomen that most people envision when they think of a black widow. Though the red hourglass is a reliable indicator, not all female black widows will have the same markings. Some black widows may be solid black, or some may have round or striped markings. Regardless of the shape of the markings, if an adult female black widow DOES have markings, they will always be bright red. 

Black Widow Appearance

Black widows are cobweb spiders. Most species of cobweb spiders are harmless to humans, and certain types are considered “false black widows” because of their similar appearance. It is best to stay away from any type of spider if you are unsure whether or not it is dangerous. The webs weaved by black widow spiders are typically asymmetrical and erratic. Their webs can be found in secluded and protected outdoor areas, but black widows are also known to enjoy dimly lit, isolated areas in basements and garages. The female black widow will spend the majority of its time very close to its web. If an adult female wanders from its web, it is likely to return shortly, especially if an egg sac is in the web. If you see these unruly webs anywhere in your home or outside, do not touch it! Black widow spiders are great at hiding in the dark, and they can quickly appear and bite you if they feel a disturbance. 


Thankfully, black widow spiders prefer to keep to themselves and will only bite if they feel threatened. Black widow spider bites most often occur on the hands and limbs due to people blindly reaching around dark corners and crevices while cleaning or organizing. The black widow does not always inject venom when it bites, but the results could be extremely dangerous if it does. Though rare, a venomous bite from a black widow can cause sweating, vomiting, dizziness, muscle spasms, necrosis, and even death. Symptoms can start to develop in as little as 15 minutes after a bite or up to several hours. No matter what, you should immediately seek medical attention after a black widow bite.

Brown recluse spiders are not an incredibly common species of spider found in Utah, but they have been identified in parts of southern Utah on rare occasions. Similar to brown recluse spiders are desert recluse spiders, and some experts believe all reports of brown recluses in Utah are actually attributable to desert recluses. These two spiders are often difficult to differentiate, but the same level of caution should be taken with both species. Including the legs, these spiders are typically no bigger than the size of a quarter. They are a brown to tan color, but they can occasionally have pale black abdominal areas, and desert recluses are occasionally a lighter shade of brown. Brown recluses, and sometimes desert recluses, have markings on their backs that are frequently referred to as violin shaped. Another easy way to identify a recluse spider is by its six eyes; most spiders have eight eyes, and only a few other species have six. 

Brown Recluse Appearance

Recluse spiders love a dry habitat, especially a desert recluse. They prefer to hunt at night, and they do not usually use their webs to catch prey like many spiders. The webs they weave are small and mostly used to nest and house egg sacs. Like many other spiders, recluses can easily find their way inside homes through cracks and crevices. Do not approach a spider that you suspect may be a recluse.


You have probably heard horror stories about bites from recluse spiders, but there is good news. Recluse spiders are not aggressive towards humans, and they typically only bite when they are being physically touched. For this reason, it is important to always wear thick gloves when rummaging around areas of your home that have been undisturbed for a long time. Like the black widow, a recluse may bite without injecting venom. If no venom is administered by the spider, the bite will most likely not be a serious medical issue. On the other hand, in the rare instance of a venomous recluse bite, the venom can quickly begin to break down the tissue around the area of the bite. The venom will cause the area of the wound to spread, and the flesh around the injection site may begin to turn black and appear as though it is rotting. If venom is injected, the recluse spider bite will feel undeniably more painful, and medical attention must be sought immediately. Because of the severe bodily damage a recluse bite could potentially cause, it is important to keep a vigilant eye out for these spiders.

This is one of the most common spiders found in Utah. The colors of yellow sac spiders are typically a pale yellow or tan, with a greenish tinge around their abdominal region. Their legs are mostly the same shade of yellow as their bodies, but the very tips of their legs are much darker. All eight eyes of the yellow sac spider are the same size and are found in two rows at the front of their heads. Including their legs, yellow sac spiders can grow up to a length of ⅝ of an inch.

Yellow sac spider

Yellow sac spiders get their name from the sacs they create and utilize instead of a more traditional web. Yellow sac spiders are nocturnal creatures that hunt at night and hide in cocoon-like sacs during the day, which they often create in the corners of walls and ceilings. When weather is warmer and pleasant, yellow sac spiders will often hide underneath leaf litter. However, when the colder months arrive, make sure to check inside shoes and clothes that are kept in dark areas, as yellow sac spiders are often found dwelling in such items. 


Yellow sac spiders are unusually aggressive, making them one of the more dangerous spiders in Utah. The most common spider bites in the state are yellow sac spider bites. The fang markings they leave behind are often mistaken for brown recluse bites. While the damage caused by a yellow sac spider bite is not as serious or life threatening as a brown recluse bite, yellow sac spider bites are painful and can cause open sores that ooze puss and can quickly become infected. Always seek medical attention if any spider bite starts to cause excessive pain.

There are several different species of wolf spiders in Utah, but differentiating them can be quite difficult due to the subtlety of the variations. A definitive characteristic of wolf spiders is the eye placement. Wolf spiders have eight eyes–two on the top of its head, two in the front of its head, and a row of four small eyes underneath the two forward-facing eyes. Wolf spiders vary widely in size depending on the species, with measurements anywhere from ⅜ of an inch to 3 inches long, though the vast majority in Utah are around 1 ½ inches.

What Does a Wolf Spider Look LIke

Many people have heard of the wolf spider, but this species is often mistaken for other kinds of spiders. Most commonly, wolf spiders are mistaken for tarantulas due to their hairy bodies and large fangs. Wolf spiders do not spin webs to catch prey; instead, they stalk, hunt, and pounce on their victims, similar to the hunting methods of a wolf. Because of their hunting methods, wolf spiders are most often found on the ground.


While a wolf spider bite is not as dangerous as a bite from a black widow or brown recluse, a bite from a wolf spider can still cause injury. Most bites from a wolf spider will be accompanied by pain, swelling, and redness. In rare circumstances, bites from wolf spiders can cause lymph glands to swell, and the area around the bite could start to turn black. Fang marks are left at the site of the bite, but the effects of a wolf spider bite should not typically last more than two weeks. 

This species of spider belongs to the funnel web family. Hobo spiders are notoriously difficult to identify, even to a trained eye. They are frequently mistaken for giant house spiders or wolf spiders; however, there are some subtle variations in appearance that will always indicate whether you are dealing with a hobo spider. Unlike similar spiders, the hobo spider has solid-colored legs that do not contain any bands of color, and its legs are shorter than a giant house spider’s legs. They are mostly brown, but they have a grayish abdominal area, with brown to yellow markings. Unlike larger species, the hobo spider rarely grows larger than 2 inches long. 

What does a hobo spider look like

As a part of the funnel web spider family, hobo spiders do not build a typical sticky web that is designed to trap prey. Rather, the hobo spider will create a funnel-shaped web. If a creature walks across or through the funnel web, the hobo spider will feel the reverberations on the web and attack its prey. While they prefer to be outdoors around bushes, rock piles, or any other location that provides shelter, they can also be found hiding between objects in basements or elsewhere in houses 


Over the years, there has been some debate about the danger a hobo spider poses to humans. A hobo spider bite was once thought of as extremely dangerous; there used to be more frequent reports of hobo spider bites causing severe blisters that could burst open and lead to dangerous ulcerations and even dead tissue. However, in 2017, the CDC took the hobo spider off of the dangerous spider list, citing that official reports of severe hobo spider bites had declined dramatically over the previous 30 years. Still, the bite of hobo spiders can be painful, at a minimum, and caution should be taken if you discover a hobo spider in your home. 

You have probably seen online videos of people finding huntsman spiders in their homes. The golden huntsman spider has been known to inhabit areas of Utah. They are also known as giant crab spiders because of their robust bodies and exceptionally long legs, similar to that of a crab. Golden huntsman spiders can grow up to 6 inches long and have brown to black bodies, and the golden huntsman is typically a yellowish color. Their bodies are generally flat, and they have two rows of four eyes. 

what does a huntsman spider look like

Sticking true to their name, the huntsman spider prefers to hunt in order to catch its prey. Golden huntsman spiders like areas around shrubbery and rocks, but they are also known for their impressive climbing skills relative to their body type and size. If a huntsman spider gets inside your home, you will most likely find it effortlessly climbing up your walls and across your ceiling.


Female huntsman spiders are known to be aggressive towards humans when they are guarding their egg sacs. Reports of bites from golden huntsman spiders are low, likely due to their frightening size that alerts humans of their presence. While not usually medically serious, huntsman spider bites are known to be quite painful and can cause serious swelling and irritation, with some cases even reported to include nausea and headaches.

Though it is even more terrifying looking than the huntsman spider, the camel spider is not technically a spider, but it is part of the arachnid family. These little monsters can grow as large as 6 inches in length, but the types of camel spiders commonly found in Utah are typically smaller. They have tan to brownish bodies that have tiny hairs all over them. Their mouthparts have strong pincers and sharp, tiny teeth that can cut through bones of their ground-dwelling prey. Camel spiders also have a trachea, which allows them to take in oxygen and move around more quickly than most spiders.

what does a camel spider look like

Similar to their namesake, camel spiders can be found in desert climates, often under rocks or other forms of shelter from the sun. They are known to let out a hiss to ward off predators, and they feed on smaller creatures like beetles, wasps, or even smaller rodents and reptiles. Their piercing mouthparts are used to cut prey into smaller pieces, which are then liquified and ingested by the camel spider. 


In all likelihood, you will not be critically injured due to a camel spider bite. Of course, bites do not have to threaten your life in order to cause you discomfort. The same piercing mouthparts that cut through their prey are what they use to bite humans when they are threatened. A camel spider bite can be extremely painful and will cause redness and swelling. In very rare cases, camel spider bites have caused serious infections to occur. Deadly or not, a bite from a camel spider should be taken seriously.

Populations of woodlouse spiders are traditionally found in coastal states, but they are also becoming one of the more common spiders in Utah. Woodlouse spiders have tan to brown abdomens, with a smooth, red cephalothorax and legs of the same color. They are one of the rare spider species that have only six eyes located above their dangerously large and sharp fangs. Woodlouse spiders only grow to roughly ½ an inch in length.

Woodlouse Spider

Like other hunter spiders, the woodlouse spider does not use a web to catch prey. They like to hide under debris and attack their prey with their dangerous fangs. These spiders commonly feed on smaller bugs like crickets, house centipedes, and lice. Woodlouse spiders are nocturnal hunters, so make sure you keep an eye out for their bright red bodies if you have to go to your garage, basement, or attic in the middle of the night. 


Woodlouse spiders will use their fangs to bite humans when they feel they are in danger. Their fangs are strong enough to pierce human flesh. The venom they inject into their prey is not known to be harmful to humans or pets, but their bite is still sure to cause discomfort. A bite from a woodlouse spider can be painful and will cause swelling and irritation.

Other Spiders In Utah

While some spiders are much more dangerous than others, no spider bite should ever be taken lightly, especially if you are not an expert and are not 100% sure what type of spider bit you. Every one of the aforementioned spiders has the capability of causing serious infection or injury. There are, of course, other spider species that may be able to bite you, but the effects of their bites are virtually harmless. 


There are thousands of species of ground spiders, none of which is known to cause serious harm. Orb-weaving spiders spin beautiful wheel-shaped webs, prefer to stay away from humans, and they are considered a non-threatening species; their bites are infrequent and do not contain a venom potent enough to seriously harm humans. Below are just a few more of the spiders commonly found in Utah that typically do not cause serious, or even moderate, harm to you and your loved ones.

  • American Grass Spider – These spiders look like tiny wolf spiders, but they are not dangerous. They rarely grow over 1 inch long, and they attack their prey using their famous speed when they feel something crawling on their webs. Their bites cause minimal irritation to humans.


  • Jumping Spider – Tiny, hairy, and almost cute, jumping spiders in Utah are not known to be harmful. They will not exceed 1 inch in length, and they are usually identified by mostly black bodies that have tiny colorful markings on their abdomens. Small bites can occur, but they are much more likely to jump, run, and hide when people get close. 


  • Cellar Spider – You have probably heard these critters be referred to as “daddy long-legs.” Cellar spiders actually seem to embrace the presence of humans, and they even benefit people by feeding on flies and other bugs. If they do attempt to bite, they will be unable to penetrate human flesh, making them truly harmless to people.


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