They eat leaves! ~ four-year-old They are so beautiful when they are caterpillars and when they are butterflies. ~ six-year-old I just love seeing how they live when they are a caterpillar, when they are a butterfly. I just love seeing their life cycle. Tiny, tiny caterpillars are so cute! ~ nine-year-old We’ve watched metamorphosis up close. A gulf fritillary caterpillar turn into a butterfly.