When Duck and Goose find a big ball in the park, they know right away what it is: an egg, of course. Hills is psychologically acute as he shows how at first they squabble over the ball, then strike a truce, sitting on it to keep it warm and making plans for teaching its "fuzzy little occupant" to swim and fly. After learning the truth from, yes, a little bird, they decide to make the best of the situation. After all, a bond has been formed, not only with the ball but with each other.