None of us are ever really alone—not with the trillions and trillions of microbes that call our bodies home. Recent scientific research has uncovered just how interdependent our relationships with these tiny "hitchhikers" are, and that lots of them are actually good for us! Filled with intriguing information and just enough yuck factor, kids will be thrilled to discover what a big deal these small "critters" who live in and on their bodies are. No hand sanitizer required!