Nature has given butterflies the best adaptations not only for their survival, but also for the survival of other forms of life which depend on them. Butterflies pass through a four-stage life cycle: egg, caterpillar, chrysalis and butterfly. The caterpillar is the growing stage of a butterfly’s life. Caterpillars are an important food source for lots of creatures. In the spring, birds feed them to their chicks, but caterpillars also form part of the diet of many other animals. All life on Earth is interdependent, so if butterflies were born as butterflies, many other forms of life would need different adaptations to survive.