What to Know About Resident Spiders in Colorado

It is important to be aware of the type of spiders in your area so you are prepared and know what is out there. So here is more info on the spiders in Colorado and what you should know about them.

Spiders in Colorado

If you live in Colorado, you are most likely aware of the various spiders that share the space with you. However, if you plan to visit this beautiful state, you might want to learn about some of the spiders living here. While these spiders will most likely not hurt you, it is to your benefit to have an idea of some of the potentially dangerous spiders that are out there. You should not be alarmed; you should be aware. 

Brown Recluse

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One of these poisonous spiders is the Brown Recluse. To your benefit, you can relax, knowing that their presence in the state is rare. Interestingly, the brown recluse is usually transported to a new location by residents relocating or visiting the state. Although their bite is not painful at first, it does have a potentially deadly venom. You should know that as one of the poisonous spiders in Colorado, it usually is not capable of penetrating most fabrics. Instead, they are notoriously known to nest in clothes and gloves that have been left undisturbed for an extended time. The smartest thing you can do is be aware if you see a suspect spider.

Hobo Spider

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Another one of the spiders in Colorado is the “hobo spider.” This little guy is often referred to as an “aggressive house spider.” If the hobo spider should happen to bite you, relax as about half of their bites do not cause any issue. Also, their bites are not known to cause fatalities in humans. If you do receive a bite, you might have some symptoms such as a painful headache, lesions, or blisters. Colorado has more than its share of this creature.

Black Widow

Spiders in Colorado also include the black widow. You can identify this one by the red markings. You only need to be concerned with half the black widow population. This is because females are the only danger to humans. Of course, identifying a male from a female is nearly impossible for the novice. It should be known that their bite is remarkably painful. It can also cause permanent damage. It seldom results in death with the modern medical treatments available. Even so, if a black widow bites you, you should consider seeking medical attention.


Another of the spiders in Colorado, which we have heard horror stories about, is the tarantula. We’ve often been told about their deadly bite; however, although they are very intimidating in their looks, they cannot cause serious damage in most situations. Just like the black widow, their bites are painful. The hair on the tarantula also irritates the skin. Even though their bites are not severe, if you should feel any symptoms from the bite, you might want to have it checked. An interesting fact about the male tarantula is that they usually wait ten years to reach their sexual maturity. Typically, they mate one time and then die. Also, they are often killed by the female with whom they choose to mate.

Yellow Sac Spider

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Another creature in Colorado to watch out for is the yellow sac spider. If this creature bites you, it is wise to seek medical attention immediately. As one of the poisonous spiders in the state, its bite is still not fully understood. It is known that their bite can cause small lesions on your body. Since the actual seriousness of the bite has not entirely been determined, it is suggested you seek medical attention.

Other Spiders in Colorado

Aside from the poisonous spiders in Colorado, there are also about 166 other species that live in the state. They are divided into two dozen different spider families. The largest of these groups is the Jumping Spiders. There are 31 spiders found within this group. Jumping Spiders make up the world’s largest family of spiders. Next is the Wolf Spiders with 19 varieties followed by Ground Spiders with 14 types. The smallest group is the Sheet Web and Dwarf Spiders with seven known species.

Most people are familiar with two spiders found in another group known as the Cobweb Spider. This group includes the Western Black Widow and the Southern Black Widow. The first dominates all spiders in Colorado. The latter is present in the state only because it accidentally hitched a ride into the state.

Spiders found in the Jumping Spiders group, and some of the Ground Spiders are so small they are difficult to identify as spiders. When photographed, the spiders in this group often need to have some type of microscope, added to a camera, to capture a picture. In the Jumping Spider group, the spiders are able to jump several times their body length. They are also capable of running fast. They have better eyesight than most other spiders. If you disturb one of these spiders, they will bite if they feel threatened. However, their venom is not any worse than a bee. They do not create cobwebs, although they can make single strands which they use for climbing. 

Funnel Spiders are the type you will find in your home in Colorado. They are mostly present during the late summer and early fall. You will find their dense mats of silk in various areas such as shrubs, corners of buildings, and thick grass. A spider in this group usually has a central retreat it uses. It then rushes into the web when any prey has entered. These spiders are harmless, although they are sometimes mistaken as a brown recluse. However, they have a darker brown color along with black markings on the abdomen. Also, they do not have the “violin” marking of the brown recluse. These spiders have four pairs of eyes as opposed to three. They are much faster in their travel.

Colorado has many species of spiders; most of them have a lifespan of less than a year. It is unusual, but all the spiders that live in Colorado have eight legs. Although none of us like to see any spider roaming around our house, we need to remember that they are a beneficial insect as they feed on other pests.