A baby butterfly is called an egg, which is the first of the four stages of life a butterfly will go through. An egg is small and hardened on the exterior. It sticks to a leaf by a rapidly hardening glue.
Butterflies are insects that go through several different stages of life when their physical structure changes dramatically. After the egg hatches, a caterpillar emerges. Caterpillars spend almost every waking moment eating. Most are herbivores, but some eat insects. Once the larva is fully grown, it enters its pupa stage, in which the caterpillar wraps itself and begins metamorphosis. When the process is complete, a butterfly emerges.