This book, like the title says, is all about sleep and rest in animals. In the foreward, the author says that the meaning of "sleep" will be stretched a bit for the purposes of the book, so there's a lot of info on kinds of "sleep" that some might not consider to be sleep. The chapter on insects is a good example of this. I like that the author often notes areas where scientists disagree. Still, if you're looking for detailed information on sleep in various animals (insects, reptiles, birds, and mammals), this would not be a good book for you. The information in this book seems to be intended more to give you a general idea about sleep and rest in these animals, with occaisional interesting details. It's a great place to start if you don't have anything specific you want to know, but it's probably not what you're looking for if you already know a lot about the subject. However, this book does have excellent pictures, and I would recommend it just for those. Every picture is full color, and some take up two whole pages.