Washing your hands with soap and warm water is very important, but do you know why? It stops germs from spreading and growing! Germs are tiny living things that can cause diseases, and there are a few key kinds: bacteria, viruses, fungi, protozoa, and prions. Readers learn all about these types of germs, how they spread and infect the body, and how the body fights them off. With fascinating illustrations, achievable texts, and helpful diagrams, readers become knowledgeable about the science behind germs--and they'll also know how to protect themselves from them!