Lynda DeWitt is an editor in the Educational Media Division of the National Geographic Society, and has published wildlife articles in various publications. She lives in Washington, D. C. Carolyn Croll is the author/illustrator of several books for children and has illustrated numerous other titles, including another Let's-Read-and-Find-Out Science Book, Switch On, Switch Off by Mel Berger. She lives in Philadelphia. Carolyn Croll is the distinguished illustrator of many books for children, including the I Can Read Books The Big balloon race by Eleanor Coerr and Clara and the Bookwagon by Nancy Smiler Levinson. She lives in Philadelphia, PA.