While experts still don't have all the answers, one fact they do know for certain is that sleep is not only important, it is essential to life! Physical, mental, and emotional health are all impacted by sleep.

The world of sleep is filled with many unanswered questions and mysteries. While the exact physiological roles of sleep are still uncertain, researchers are confident that the body does a lot of valuable work while sleeping.

Sleep outlines everything we know about sleep in clear...and sometimes humorous...language perfect for young readers.

Topics covered include...

• the four stages of sleep (including REM sleep and Deep Sleep), their purposes, and what happens to the body during each

• sleep disorders, such as sleep apnea and narcolepsy

• how various animals sleep

• where people sleep and the types of bedding used throughout the world

and more...