Doreen Cronin is a children's book author born in Brooklyn, New York. She grew up on Long Island with her parents and siblings. Cronin's first grade teacher recognized her talent for writing. She went to college and law school, then began practicing law in Manhattan while continuing to write. Cronin's first published book was Click, Clack, Moo: Cows That Type, which won several awards. She is best known for her Diary of a Worm, Diary of a Fly, and Diary of a Worm series told from the perspective of bugs.