You've probably heard about the phenomenon in which wild tarantulas embark on a pilgrimage across Colorado in hopes of finding a mate. While these tarantulas aren't necessarily very dangerous to humans, there are four spiders that you may come across in Colorado that are.

Dangerous Colorado Spiders: Black Widow

Of course, if you grew up in Colorado you already know to avoid Black Widows, but it's likely that you only know what a female looks like.

Females have a big, round, black abdomen with the trademark red hourglass, while males are about half the size of the females with orange, white, and black colors on their abdomens. It's only the females who are able to bite humans, but rarely will unless provoked.

However, if you do get bit and are a healthy adult, you'll probably be fine, but you should still go immediately to the hospital as symptoms of a Black Widow's bite include muscle pain, nausea, paralysis of the diaphragm, and trouble breathing.

Dangerous Colorado Spiders: Brown Recluse

Another dangerous spider you've likely heard of in Colorado is the Brown Recluse. These spiders are completely brown in color with a violin-shaped marking on the top of their body.

While a bite from a Brown Recluse is serious, causing things like necrosis, extreme discomfort, and possibly permanent scarring, they're not native to Colorado and rarely survive the winter. Regardless, you should still go to the hospital if you believe you've been bitten.

Dangerous Colorado Spiders: Brown Widow

The Brown Widow is nearly identical to the Black Widow in that only the females bite humans, they're about the same size, and a bite from one of these spiders can result in pain, muscle rigidity, vomiting, sweating, and even abdomen pain that mimics appendicitis.

The biggest difference between the Brown Widow and Black Widow is the coloring as both sexes are lighter in color and females have an orange hourglass on their abdomen. The bite is reportedly less serious than that of a Black Widow and they are a timid species that rarely bites humans, but, again, it's definitely recommended to go to the hospital if bitten.

Dangerous Colorado Spiders: Black-Footed Yellow Sac Spider

Finally, the last of these four dangerous Colorado spiders is known as the Black-Footed Yellow Sac Spider. As their name suggests, these spiders are pale yellow in color with brown markings and an orange stripe that runs down their abdomen.

These spiders are pretty timid and rarely bite humans, but if you do get bit you'll experience pain, itching, and swelling for roughly seven to ten days.

Regardless of the bite, if you experience any of the above symptoms and/or believe you've been bitten by one of these four spiders, you should definitely go to the hospital right away.

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