Reptiles, fish, some insects (such as butterflies), and some birds (on their legs) have scales. Scales are one solution that help animals adapt to their environment. Scales can be used to protect an animal's skin from harsh conditions such as hot, desert climates. Modidified scales can also help animals to regulate their temperatures by cooling off the animal (scientists believe that the Stegosaurus used giant scales on their back primarily for this purpose). Butterfly scales are extraordinarily small and are responsible for the color found on their wings. Some animals such as fish and butterflies regularly lose their scales in order to protect the animal from predators (such as parasites and spiders).