Snakes Biggest! Littlest!

Up-close look at the parts of snakes that allow them to live in their specific place in the world.

Sandra Markle has written more than seventy nonfiction books about science for children. She has won more than thirty awards for her work. In addition to her books, Ms. Markle has developed science specials for television as well as Internet-based educational programs. She lives in New Zealand.

Joe McDonald has been photographing wildlife since he was in high school. He has been published in every natural history publication in the United States, and has also published seven books on wildlife photography. He lives in McLure, Pennsylvania, with his wife and fellow photographer, Mary Ann McDonald.