Many of the snazziest decorations in the animal kingdom are charm offensives, put on by creatures trying to mate.

While some of these adornments, like a peacock’s tail feathers or a moose’s antlers, are obvious even to humans, others can be perceived only with sensory capabilities that we don’t have.

A new study, published on Monday in the Proceedings of the National Academy of Sciences, offers the first evidence of one such display: cuttlefish dazzling potential sexual partners by creating a pattern on their skin, based on the orientation of light waves and invisible to the human eye.

When humans (and most other mammals) see light, we can’t discriminate between waves of light that are bobbing up and down vertically as they travel and waves of light weaving horizontally, from side to side. But lots of animals, including some fish, insects and soft-bodied sea creatures like cuttlefish, can perceive the orientation of light waves’ oscillations as those beams move through air or water. If light passes through a filter that blocks some of those orientations, the light is said to be “polarized.”

Since we can’t perceive the orientation of light waves, “it’s really difficult to know exactly what polarized light looks like to an animal that can see it,” said Arata Nakayama, an author of the study and a research fellow at the National Taiwan Normal University. As far as researchers can tell, polarization adds contrast or texture to what an animal sees, which can help make objects stand out more clearly against their surroundings.