Book excerpt: Some animals look so alike, it's difficult to tell which is which! The Aardvark or Anteater book in the Which Is Which? series helps readers discover the similarities and differences between aardvarks and anteaters. Focused on 21st Century content, the Which Is Which? series encourages readers to ask questions, think more critically and creatively, and use their problem-solving skills. Book includes table of contents, sidebars, glossary, index, and author biography.