Flap Your Wings is a 1969 book written and illustrated by P.D. Eastman.
The book begins with an egg laying in the path. A boy walks up and asks whose egg is this. No one answers. Then the boy sees a tree with an empty nest. He assumes that the egg belongs in the nest. He climbs up the tree and puts it there. Then he walks away.
Two birds fly to their nest and are surprised to see such a large egg in their nest. Mr. Bird says it doesn't matter whose egg it is since it's in their nest, and they must hatch it to keep it warm. They take turns sitting on the egg and sometimes both birds sit on it together.
Then one day, Mrs. Bird hears a squeaking noise, which means that the baby is ready to come out of the egg. The egg cracks open and out comes the baby, who is a lot different from the two birds. Mr. Bird says that the baby, Junior, is their own young, and when his mouth is open, it means he is hungry and needs to be fed. The birds feed him too many until he outgrows the nest.
Now, Junior is too big for the nest. Mr. and Mrs. Bird teach him how to fly like a bird. They tell him to jump off and flap his wings like a bird. Junior does so, but he falls into the water. It's just right for Junior. Mrs. Bird doesn't believe that Junior is a bird at all, but it doesn't matter what he is.
- This book was originally published as a Random House Early Bird Book. It was republished as a Beginner Book in 2000.