"Quiet, pleasing ink-and-watercolor pictures illustrate the text, and an attractive two-page classification chart shows 'Life on Earth,' divided and subdivided into categories. This picture book provides young children with a simple, informative, age-appropriate introduction to mammals."-- Booklist "Largely eschewing scientific vocabulary in favor of clear explanations (the terms 'vertebrates' and 'invertebrates' are introduced in a diagram in the backmatter), Rockwell's text focuses on the concepts. The fine-lined ink-and-watercolor illustrations are as clear and straightforward as the text, with the carefully labeled renderings of the animals examined particularly meticulous. A clear, respectful introduction." -- Kirkus Reviews "Ink-and-watercolor illustrations are detailed and complement the text nicely. A solid option for classrooms and libraries"-- School Library Journal "[Readers will] learn plenty about the ways that animals are categorized and classified." --Publishers Weekly.