Opossums Glow Pink Under UV Light

North America’s only marsupial already has an impressive résumé. Opossums are naturally resistant to rabies thanks to their unusually low body temperatures, and they can withstand many snake venoms thanks to protective compounds in their blood. But perhaps their strangest superpower only appears after dark.

Shine an ultraviolet light on a Virginia opossum, and its pale fur glows a brilliant hot pink. This phenomenon, known as biofluorescence, occurs when an animal absorbs ultraviolet light and re-emits it as a visible color. Scientists have discovered biofluorescence in everything from flying squirrels to platypuses, but they still aren’t entirely sure why some mammals glow. It may help with communication or camouflage — or it could simply be an unexpected byproduct of their fur.