Camouflage
Butterflies' primary structural adaptation is in their wings and how they use them to conceal themselves. The wings of many species have evolved to mimic their surroundings, with the green hairstreak a particularly good example. These butterflies have wings that are colored and shaped to look exactly like the leaves the butterfly is found on, meaning that it is far harder for predators to locate.
Disguise and Subterfuge
Many butterflies have evolved "eye spots" on their wings. When their wings flash open, these spots give the butterfly the appearance of a much larger creature, frightening off potential predators. Similarly, the viceroy butterfly deliberately mimics the appearance of the monarch butterfly, which has evolved to be toxic to eat. As a result, predators are discouraged from preying on both species.
Basking
Butterflies are cold-blooded creatures, meaning they need to warm their wings up before taking off. This is where they are at their most vulnerable to predators, but it's a vital part of the butterfly's progress. The butterfly can simply fold up its wings if it gets too hot.
Light Sense
Every fourth generation of monarch butterflies migrates 2,000 miles, traveling from as far north as Canada to overwintering spots in Mexico. Scientists such as Carol L. Boggs et al. describe how the monarchs use their antennae to detect the basic level of light around them. This allows them to tell the time of day depending on how much light they can see, and this in turn allows them to stay on target.