Eggs can be laid in spring, summer or fall. This depends on the species of butterfly. Females lay a lot of eggs at once so that at least some of them survive.

Butterfly eggs can be very small.

The job of the caterpillar is to eat and eat and eat. As the caterpillar grows, it splits its skin and sheds it about four or five times. Food eaten at this time is stored and used later when the caterpillar becomes an adult.

Caterpillars can grow 100 times their size during this stage. For example, a monarch butterfly egg is the size of a pinhead and the caterpillar that hatches from this tiny egg isn't much bigger. It will grow up to two inches long in several weeks.

Depending on the species, the pupa may be suspended under a branch, hidden in leaves or buried underground. The pupa of many moths is protected inside a cocoon of silk.

This stage can last from a few weeks to a month or even longer. Some species have a pupal stage that lasts for two years.

It may look like nothing is going on, but big changes are happening inside. Special cells that were present in the larva are now growing rapidly. They will become legs, wings, eyes and other parts of the adult butterfly. Many of the original larva cells will provide energy for these growing adult cells.

The adult stage is what most people think of when they think of butterflies. They look very different from the larva. The caterpillar has a few tiny eyes, stubby legs and very short antennae.

The caterpillar's job was to eat. The adult's job is to mate and lay eggs. Some species of adult butterflies get energy by feeding on nectar from flowers, but many species don't feed at all.

Flying comes in handy. The adult female can easily fly from place to place to find the right plant for its eggs. This is important because caterpillars can't travel far. Most adult butterflies live only one or two weeks, but some species hibernate during the winter and may live several months.