SARAH ALBEE is the author of Poop Happened! A History of the World from the Bottom Up and dozens of books for young readers, three of which have been New York Times bestsellers. She lives in Connecticut with her husband, three kids and dog. She blogs about offbeat history topics at sarahalbeebooks.com/blog.

ROBERT LEIGHTON is the illustrator of Poop Happened! A History of the World from the Bottom Up and What's Going on Down There?, as well as a puzzle-writer and New Yorker cartoonist. He lives in New York City.