Underwing moths (Catocala spp.) are known for having dull, camouflaging forewings, and brightly colored hindwings which they suddenly flash open if disturbed. It is believed that the patterning of the hindwings resembles the eyes of a predatory animal, such as a cat. A bird or other small predator that is not used to this display is likely to be frightened, allowing the moth to escape.

Of the more than 250 known species, slightly less than half are found in North America—mostly in the United States—while the rest occur in Eurasia.