Sally and Nick are pretending to be birds, because it's fun to fly! But not all birds can fly, says the Cat. His friend Os the ostrich can't fly, but he can do oh so many other things! Why don't they go meet him and try to guess what he's best at doing? Off to Savannah Saloo! They guess that he's good at being big, a really fast runner, growing beautiful feathers and seeing really far away! But those aren't what he does best. They meet Os' wife and ostrich chicks and realize that being moms and dads are what ostriches do best! Just like Nick and Sally's moms and dads!