Bat sees the world upside down. All the other animals think he's ridiculous and, of course, wrong. They tell him he's wrong ("daft") when he says that he needs an umbrella to keep his feet dry, or that the rising water of the river will get his ears wet. But when Bat finally asks them to hang upside down from a tree limb, they see the world as he does, and they understand that Bat wasn't wrong--he's just seing things from a different point of view.
This is an excellent book that teaches a valuable lesson in a very entertaining and approachable way. You have to flip the book upside down to read parts of the text, which kids will find quite funny, and the expressions on some of the animals faces are just priceless.