Diane de Groat Diane deGroat is the illustrator of more than 150 children's books and the author-illustrator of bestselling books about Gilbert, including Ants in Your Pants, Worm in Your Pants (Gilbert Goes Green); April Fool! Watch Out at School!; Mother, You're the Best! (But Sister, You're a Pest!); Last One is a Rotten Egg!; and the New York Times bestseller Roses Are Pink, Your Feet Really Stink. Most recently she has worked on the Charlie the Ranch Dog series by popular blogger Ree Drummond. Diane lives in Amherst, Massachusetts.