I was read this book (my whole class was) by our 4th grade teacher in 1984. The hairs on the back of my neck stand up every time I think about this story, and cannot wait until my now 3rd grade son is just a bit old so I can finally read it to him. The movie that followed was a nice Disney tribute, but this book is absolutely WONDERFUL! I think I'm going to re-read it again soon after thinking about it again. It was based on Professor Calhoun's early Utopian studies with mice in what he called the Universe 25 studies. Seriously fascinating.