Butterflies go through four life stages, and they look very different at each stage . 1. An adult butterfly lays eggs.2. A caterpillar hatches out of the egg.3. The caterpillar forms a chrysalis or pupa.4. The chrysalis matures into a butterfly.. Stage 1- Eggs. The adult mother butterfly lays a number of eggs on the leaves of plants which she recognises by smell.She knows the leaves will be good for the baby caterpillar to eat..