It’s that time of year again, when thousands of eight legged arachnids come out of their southeastern Colorado hiding places, looking for love. 

Maia Holmes, Education and Outreach Coordinator for the Dept. of Agricultural Biology at Colorado State University explains why this species in particular are on a walk about right about now.

These tarantulas are a native species that live in Colorado throughout the year. In the fall, the male tarantulas are out looking for females because it is mating season for them. The mature males will likely die by the end of fall after mating, but mature females will continue to live in their burrows for decades. Each egg case that a female produces can contain up to 1500 baby spiders in it!

The number of tarantulas that we see during this annual mating season appears to be declining. In the past there have been hundreds of tarantulas out at night, but in recent years you are more likely to see dozens instead of hundreds. This is likely related to climate change, an increase in droughts and possibly human activity.