Ages 6 to 12 years. Few books explain the scientific classification of animals as well as this one. All creatures, including insects, mammals, and fish, are classified and described from simple animals like sponges to the larger brained mammals such as humans. Young readers will learn: all the basics of kingdoms and species that form an important foundation for the study of biology; the threat to habitats by illegal hunting, human development, and pollution; how readers can help prevent their destruction.