Each year, thousands of hairy tarantulas march through Colorado in search of a mate. Whether you’re looking to view this spectacle or avoid it entirely, it’s important to know when it’s happening and where.
Generally, tarantulas start to show up in big numbers in the La Junta and southeast Colorado area starting in late-August, crawling around the area through early October. The migrating tarantulas are almost all males looking for a female mate. According to Whitney Cranshaw, an Entomology professor at Colorado State University, these males are “Oklahoma brown” tarantulas, seeking the typically less transient females that burrow in Colorado’s prairies.
According to Paula Cushing, a biologist at the Denver Museum of Nature & Science, these males are likely around 10 years old.
The local tourism board seems to embrace the natural phenomena, listing viewing tips that include optimal times and places to spot the spiders. They recommend Highway 109 south of La Junta on Comanche National Grassland at around 6 p.m., with Sept. 10 typically being the peak day.
Though tarantulas are one of the largest spiders in North America (the Carolina wolf spider is even bigger), they’re mostly harmless to humans and are popular pets. They are still able to deliver a powerful bite that can sometimes result in injury or allergic reaction. They’re also known to fling their tiny hairs at attackers in defense. These hairs are known to be very irritating to human eyes, mouths, and the nose, at times requiring medical attention.