Although this book is thorough in describing the differences between viruses and bacteria, I think it misses an important opportunity to reinforce hygiene...wash your hands, cover your mouth etc. These are given a cursory review on the last page, with no accompanying illustration. I had hoped that this book would help my almost-4-year-old to understand how people get sick, how they get well, and how they can help prevent communicable disease to reinforce what I teach at home. I do not think that the authors did a very good job of meeting those expectations.

My three-year old son really enjoys this book. The book's fairly simple, yet informative account of how viruses and bacteria can make us sick helps to make the abstract concept of germs more concrete for him. As an added bonus, the book gives a plug for handwashing, covering mouths when sneezing or coughing, and not sharing cups that most preschoolers can benefit from. I must also confess that, despite having read the Times Science section for years, I learned quite a bit about viruses and bacteria from this simple, well-illustrated book. A good buy, especially for parents who field a lot of factual queries every day. The Let's Read and Find Out series is a great way to let someone else do the explaining for a change.