"Bacteria are the smallest of the small! These one-celled organisms live everywhere on Earth, and while most are harmless (or helpful), some can cause a lot of damage through disease. In this book, readers will learn more about bacteria, including their history (they were among the first life-forms on the planet), their life, and how they can cause trouble. Fascinating details pull readers into the text, while full-color photographs show these tiniest of terrors up close"--