Every animal goes through stages of life: it is born (or hatches), it grows up, it becomes an adult, and it can have babies of its own. This pattern of stages is called a life cycle. Different animals have different life cycles, but they all follow this basic pattern.
Draw the life cycle of a chicken (egg, chick, hen/rooster) as a circle diagram. Compare it to the life cycle of a dog (puppy, young dog, adult dog). Talk about your own life stages so far and what comes next.
Every animal you see was once a baby. And every adult animal can have babies that will grow up just like it did. This repeating pattern of stages — from baby to adult to having the next generation of babies — is called a life cycle.
Most animal life cycles have the same basic stages. First, the animal starts life. Some animals hatch from eggs — birds, reptiles, fish, frogs, and insects all begin as eggs. Other animals, like dogs, cats, and humans, are born live from their mother. However life begins, every animal starts small and helpless.
Next comes growing up. The young animal gets bigger, stronger, and learns the skills it needs to survive. A puppy learns to run and bark. A chick grows feathers and learns to fly. A tadpole grows legs and loses its tail. Growing up takes different amounts of time for different animals. A fruit fly grows up in a few days. An elephant takes about 15 years to become fully grown. A human takes about 18 years!
When the animal is fully grown, it is an adult. Adults can find their own food, protect themselves, and — most importantly — have babies of their own. When those babies are born or hatch, the cycle starts all over again. A mother chicken lays eggs. Those eggs hatch into chicks. The chicks grow into chickens. Those chickens lay more eggs. Around and around it goes.
That is why the life cycle is drawn as a circle: there is no real ending. Each generation starts a new trip around the same path. The life of any single animal has a beginning and an end, but the cycle of life from parents to babies to new parents keeps going and going.