Hobo Spider
The Hobo spider is a hairy light brown spider with tan, darker brown, or black markings on the thorax. While it's not the most dangerous spider we see in the field, it does bite humans. The bites can be ugly and unpleasant, eventually turning black and discharging fluid—reason enough to get these creatures out of your home.
Black Widow Spider
Many people in Denver believe black widows don't exist in Colorado, but they'd be very wrong. They can easily invade basements in our area. Many Denver residents also believe them to be solitary, but don't be fooled. Each female black widow produces 6 to 12 egg sacks in her lifetime containing 200 to 400 eggs. It doesn't take them long to produce a dangerous infestation.
Yellow Sac Spider
You can find the Yellow Sac spider both indoors and out in the Denver area. These spiders are pale yellow to a yellowish-green and look almost transparent.
As with the Hobo spider, there are varied reports of the level of toxicity of their bite. Their bite can cause an instant and intense stinging pain and a small red welt that itches for about a week.
Brown Recluse Spider
Often misidentified as Funnel Web or Wolf spiders, the Brown Recluse has a buckskin color and dark brown legs. The violin-shaped marking on its back and only three pairs of eyes are identifying factors.
At the initial bite site, a painful blister may form. Sometimes an ulcerous, slow-healing wound may form. The bites can cause severe pain, fever, chills, nausea, joint pain, and seizures.
