What makes an invertebrate an invertebrate? How is an invertebrate different from a vertebrate? Why do insects molt? Classifying Invertebrates looks at the amazing class of animals with no backbones. Find out how invertebrates are grouped into orders and how each one is different from the rest. From flatworms to roundworms and sponges to echinoderms, discover what makes invertebrates so special. Classifying Living Things investigates how and why we group animals. Each book focuses on a particular class of living things, looking at the key characteristics that set its members apart from those of other classes. Discover how classes of living things have evolved, and how species have adapted to suit their environments. Find out why certain invertebrates may show some characteristics of a particular class but actually belong to another."