Life Cycles

View Transcript Hide Transcript A monarch butterfly emerges from the chrysalis. © www.istockphoto.com/Jacob Hamblin

A monarch butterfly emerges from the chrysalis.

A brand-new life begins when an animal is born or hatches from an egg. This new animal grows and changes over time. As animals get older, they grow stronger and begin to look different. When an animal has finished growing, it becomes an adult. The steps of change in an animal’s life are called that animal’s life cycle.

In time, adult animals produce their own young. Most birds, fish, and insects lay eggs when they are ready to start a family. Nearly all mammals give birth to live young. Under the watchful eyes of their proud parents, these new baby animals begin their own life cycle.