These exuberant books in the Wildlife Wonders series feel greatly, and sometimes even a bit overwhelmingly, informative. Each spread is full of text, interesting facts, and photographs set against a vividly colored background. The subtitles give a clearer sense of the books' focus than the title questions, which receive no more space or attention than the volumes' other main topics. Rather, the books focus on adaptation and unique features of wildlife within the context of evolution. In each book, a large family classification chart is crammed onto one spread. Despite the busy, crowded pages, the content feels fresh. Well-chosen photographs illustrate and enhance the ideas in the text. Why Do Mammals Have Fur? successfully covers a broad range of information but lacks the sense of depth that the other books in the series have. Readers will likely feel proud of all they learn from these books.