A female chicken is called a hen, a baby chicken is called a chick, and a male chicken is called a rooster. A baby chick's life cycle starts when its mother hen lays an egg. This egg has a big yellow yolk that contains all the food the chick needs while it grows inside the egg. The yolk floats in the egg white, which protects it and contains water for the chick. For about 21 days the hen sits on her eggs, covering them with her feathers to keep them warm. Several times daily she turns the eggs with her beak, which keeps the yolk from sinking down and crushing the chick against the shell.
When it is time for the chick to hatch, it pecks holes in the shell with a bump on its beak called an egg tooth. A few days after the chick has hatched, the egg tooth falls off because the chick no longer needs it! A baby chick has to take lots of breaks to rest, and when it finally gets out of the shell it doesn't get up and move right away -- getting out of that egg shell was hard work and the baby is too tired! Its feathers are wet and stringy, but they soon dry and become fluffy.
Baby chicks grow up quickly. Young girls are called pullets and young boys are called cockerels. Pretty soon they will be grown-up hens and roosters and start having their own babies!
All birds lay eggs, but they don't all do it in exactly the same way: