This full-color book of marvelous mammals provides 30 hands-on activities to give interested children an overview of the wide varieties of mammals in their world  How big is a blue whale? Why does a sloth crawl from the safety of a tree to the ground once a week? How does a vampire bat feed?   Young nature enthusiasts will find answers to these questions and learn all sorts of fascinating facts about mammals in this full-color, interactive book. Mammal Mania explores what makes mammals unique, as well as their anatomy, behavior, and conservation needs.    Readers will learn to build a squirrel feeder, write a putrid poem, make an animal tracking station, and much more.   Thirty hands-on activities promote observation and analysis, writing and drawing, math and science, and nature literacy skills.   Young Naturalists is a kid-friendly series that introduces zoology and botany for upper elementary and middle-grades readers.