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Colorado Spiders 101

Spiders strike fear into many and it is no wonder why considering they commonly occur in horror movies and haunted houses as creepy-crawly creatures of the night which are portrayed as gruesome predators.

There are many myths surrounding spiders too, which do not help their image. For the most part spiders in The United States pose little to no threat to humans. Likely the most substantial species of concern in Colorado is the black widow. A common myth however is that brown recluse spiders are a native species in the state. Although increasing shipments and residents moving in from out of state can lead to increased sightings of the brown recluse, they are not indigenous to the state and do not typically survive long should they accidentally transfer here. Spider species often have a very similar characteristic which commonly leads to misidentification. Below is a guide to some of the commonly found spiders in Colorado including potential health threats they pose.

Black Widow Spiders

Black widow spiders are black and shiny and depending on the subspecies, they commonly have a distinct red hourglass marking. The subspecies of the spider does however determine the location of the markings. They prefer secluded, undisturbed locations near ground level to build their webs. Wood piles, crawlspaces, closets, utility, and sprinkler boxes are common hideouts for black widows. Male black widows are rarely known to bite; however, females can be more aggressive and will often bite in defense, especially when eggs are present. It was previously believed that female black widows killed and consumed males after mating, which is where their name originated. More recently, research has determined that is actually a rare occurrence in a natural setting. Black widow bites often result in a fever, increased blood pressure, nausea, abdominal pain, and sweating.

Jumping Spiders

Jumping spiders are compact in size and shape with short legs. They have a keen vision with the ability to detect movement up to 18 inches away and while that may not seem fair, it is to a spider. Jumping spiders have been known to bite in defense if they feel threatened although they are not considered a threat to humans. Unlike most spider species, jumping spiders are primarily active during the daytime. Their web retreats are often found both indoors and outdoors. They often hunt near windows or other areas of light that attract insects. Jumping spiders have a furry appearance that is primarily black. Some species of jumping spiders have brightly colored markings.

Cellar Spiders

Commonly confused with daddy-long-legs, cellar spiders are true spiders and while they do possess venom, it is not considered a threat to humans. Cellar spiders have very long legs and spin untidy webs most commonly high in corners of rooms, crawlspaces, garages, or other undisturbed locations. They are found throughout The United States and are very common in Colorado. 

Wolf Spiders

Aside from tarantulas, wolf spiders are one of the largest species of spiders in Colorado. They do not spin webs in which to capture their food, instead, they are efficient ambush predators that hunt down their food. Wolf spiders have a furry appearance and are often brown to gray in color. They may bite in defense although they are not considered harmful to humans. 

Funnel Weaver Spiders

One of the most commonly encountered spiders in Colorado, funnel weavers are brown to gray with black markings. They resemble a common grass spider with the exception of their webs which have a distinct funnel-shaped lair when the funnel spider lies in wait for prey to become entangled in their web. They do not commonly bite unless they feel threatened and are not considered harmful to humans. Funnel weaver spiders are commonly found in corners near light sources, along with windows on the exterior and in bushes/shrubs (especially juniper bushes). 

Contact us today before you start noticing spiders in your home.