In colder daytime temperatures, butterflies use their wings to reflect sunlight onto their thorax where the wing muscles are attached. Butterflies can also soak up heat from warm rocks by resting on them. If the sun still doesn't provide ample heat for a butterfly to move, the butterfly moves its wings in small increments, which will gradually warm its wing muscles, enabling it to fly. Butterflies frequently fly in short bursts on cool days because their bodies get colder during flight, as well as when cool breezes move over their wings. At night, butterflies roost to protect themselves from the cold. Some butterflies migrate, which is a trip over a very long distance. To make this type of trip, butterflies need to store energy and eat lots of food. The most famous migration is that of the Monarch butterfly