The real answer is that butterflies are not nocturnal and therefore never used celestial navigation to travel or migrate, as moths have throughout history. Some moths will mistake artificial light for moonlight. Most moths are nocturnal but a few species can be seen during the day, just not sitting out in the Sun as butterflies do. Some butterfly species are active at dusk but most are day active and do not use moonlight for navigation. Moths that travel and migrate will use moonlight when the Moon is visible but also have internal geomagnetic compasses. Migrating butterflies, such as the Monarch, use the Sun and Earth's magnetic field to navigate. Butterflies do not migrate during the night.