The ornate jumping spider is the first animal to be found to see ultraviolet B light, which it uses during mating.

For people, ultraviolet B (UVB) is an invisible, cancer-causing ray to be blocked with sunscreen and dark glasses, but for a species of jumping spider, the light sets a romantic mood. In the first evidence of an animal having the ability to see UVB, researchers have found that the ornate jumping spider uses the light in mating displays.

http://sciencenow.sciencemag.org/cgi/content/full/2008/501/2