The three sets of animals in this book include mammals, insects and birds. The first six-page section contrasts the giant golden-crowned flying fox bat with the bumblebee bat. The introductory photographs provide a sense of the difference in size. The fox bat can be five feet across from wing tip to wing tip while the bumblebee bat measures about an inch. Other photographs with informative captions show the bats in their natural habitats and a map shows where they live. Inset boxes provide Fast Facts, such as "There are very few bumblebee bats." The next two sections follow the same format. The large atlas moth is compared to the pygmy moth. Atlas moths have wingspans of about twelve inches. They live in Southeast Asia. Tiny pygmy moths live all over the world. The caterpillars eat the insides of leaves causing damage to plants. The last comparison is an ostrich to a bee hummingbird. Ostriches, which live in Africa, can run very fast, but they cannot fly. Bee hummingbirds weighing less than a penny are found in Cuba. The book begins with a table of contents and a short glossary. It closes with a page about the extinct giant moa, a bibliography, a list of internet addresses, and an index. An appropriate introductory information book for young children. Part of the "Biggest vs. Smallest Animals" series. Reviewer: Phyllis Kennemer, Ph.D.