Why do you get sleepy? When you feel tired, your body is telling you that it needs a rest. Everyone needs sleep. Babies need lots of sleep. Grown-ups need less. But no one can go without sleep for long. A team of scientists stayed awake for as long as they could to see what could happen. Read and find out some wide-eyed facts about the science of shut-eye. This nonfiction picture book is an excellent choice to share during...