For a variety of reasons, some insects inspire loathing while others are adored. The cockroach, for example, commonly inspires disgust. Butterflies, on the other hand, are celebrated in literature, painting, photography, and generally admired as a thing of beauty.
What separates the butterfly from the cockroach are the wings, those delicate, colorfully patterned membranes that butterflies flap as they flutter by. There are roughly 17,000 species of butterfly, and each comes with its own distinct wing color scheme.
The scientific name for butterfly is Lepidoptera, which means "scale wing" in Latin. Appropriately enough, butterfly wings are covered with tiny, overlapping scales that give wings their distinct look. On their surface, the scales harbor microscopic structures that create color by refracting light. Furthermore, the scales themselves are colored. Like pixels on a computer screen, differently colored scales group together to form patterns.
Wing patterns including spots, stripes, and bands serve a variety of functions. They can be a defense mechanism against predators by helping the butterfly blend into its surroundings and by making the butterfly appear larger. Some wing patterns are meant to look like the face of another animal to scare predators away. Colors and patterns are also used to attract mates; dark colors are useful for soaking up the sun.
Butterfly wings are as delicate as they look. Once ripped or torn they do not repair themselves. Yet at least some wings are incredibly durable; they manage to carry monarchs thousands of miles across the United States on their annual migration to Mexico.