Some tropical frogs can perform a neat trick: They glow in the dark! Scientists from Florida State University shone flashlights that gave off five colors of light, including blue, on more than 150 species of frogs in South America. They found that all the frogs were biofluorescent. Their skin absorbed the light and reemitted it as a different color—either orange or green.

The frogs’ glow was strongest under blue light, which is abundant at twilight—the time when the animals are most active. The green glow may let frogs communicate. That’s because their eyes are uniquely adapted to see this color, says Courtney Whitcher, a biologist who worked on the study. She adds that an orange glow may help frogs hide from predators since leaves also give off this color under blue light.