The Bromeliad Trilogy : Truckers, Diggers, And Wings

In a world whose seasons are defined by Christmas sales and Spring Fashions, hundreds of tiny nomes live in the corners and crannies of a human-run department store. They have made their homes beneath the floorboards for generations and no longer remember, or even believe in, life beyond the Store walls. Until the day a small band of nomes arrives at the Store from the Outside.