Why Do We Sleep?

Everything you ever wanted to know about sleep but were too exhausted to ask. > What are circadian rhythms and how do they affect our energy levels throughout the day. What are dreams for and how do they happen. What are the different stages of sleep. Do animals experience sleep the same way we do. With clear texts and bright, distinctive illustrations, this is a great introduction to a subject that has fascinated us since ancient times, and an engaging tie-in to biology and natural sciences curriculums.