This summer in the Colorado Rockies we encountered a number of different yellow flowers.

Some of those flowers were “decorated’ with yellow crab spiders.

Crab spiders are named for the way their front legs direct forward, like a crab.

They are known for their ability to change color to match the flower they are sitting on. Obviously this one had been recently sitting on a yellow flower.

The color change isn’t to fool their prey, however. Crab spiders like this one often glow ultraviolet, a color we can’t see but insects like bees can see. Why do you think that crab spiders are visible to insects, but try to match the flower to vertebrate eyes?

Watch out flower fly!