If you are asked to picture an animal, what comes to your mind first? A dog? A bird? Perhaps a zebra? Chances are you thought of a vertebrate, an animal with a backbone. But vertebrates, which include the animals we are most familiar with--mammals, birds, fish, reptiles, and amphibians--actually make up less than 5% of all animal species. All the rest of the animals alive today--more than 95%--are invertebrates, animals without backbones. Can you picture a spotted ladybug, spiny sea urchin, or slimy garden slug? ANIMALS WITHOUT BACKBONES: INVERTEBRATES explores the lives of the many fascinating creatures.