After his full-length adult novels, Herriot successfully turned some of his episodes into children's books. Colorfully and appealingly illustrated, the story of Moses the kitten who is raised by a pig, or the adventures of a small, lost lamb make wonderful picture books for preschool and elementary readers. The episodic structure becomes a strength because it holds the attention of the younger reader. In these books, the animals play the main role, and human characters are secondary and only supporting.