The Bromeliad Trilogy: Truckers/Diggers/Wings

First published individually in 1989 and 1990, The Bromeliad Trilogy: Truckers, Diggers, Wings by Terry Pratchett tells the story of a small band of four-inch-tall nomes, led by young Masklin, who join a larger society of nomes living in a human department store. When they learn that the Store is to be destroyed, various rival factions come together to find safety, and learn the surprising truth about their origins.