Many butterflies use eye spots, like peacocks, for defense. The spots are a common form of defense that use a pattern on the top, underneath, or both sides or their front and back wings. Some butterfly species have two large eye spots on their rear wings. When a predator approaches, the butterfly will suddenly show its eye spots and frighten the would-be attacker away. Other butterflies only have small eye spots. The spots are usually positioned on the edge of the wings. These spots are used more to puzzle the predator and cause the animal to attack the eye spot. If the butterfly is attacked, it can still fly away with minimal loss. Swallowtail butterflies, and other species like them, take eye spots to another level. These butterflies have tails on their hind wings with their eye spots. Predators confuse this combo as an antenna and eyes and can't predict the direction that the butterfly will move.
Leaves a Bad Taste in Your Mouth
Some butterflies are poisonous or foul-tasting. Bright colors usually warn a predator that a butterfly is bad-tasting. A predator, having suffered the results of consuming a toxic or foul-tasting butterfly, will have no problem remembering the bright colors. The animal will learn to avoid that color pattern.
Being tasty is not a good thing for a butterfly and because of this many species use mimicry. This is a handy defense for butterflies who are tasty and brightly-colored. Their color patterns have evolved to appear like some of their foul-tasting relatives. A good example is the brightly-colored Viceroy whose orange and black pattern is extremely similar to the toxic Monarch. Any predator that survived a Monarch the first time would never again eat something orange and black.