In rhythmic words and affecting pictures, this inviting picture book introduces young children to a world of sleeping creatures. Some animals, like bats, sleep upside down, while others, like koalas and lions, snore up in the trees. Sharks, on the other hand, sleep with their eyes open wide so they won't miss a potential meal. Animals large and small all have good reasons for sleeping the way they do, and Kimiko Kajikawa explores their particular and often humorous habits in this charming ode to bedtime.