The Borrowers — Mary Norton

Beneath the floorboards of a quiet country house lies the miniature world of the Borrowers. The Clock family -- Pod, Homily, and their daughter, Arrietty -- live happily in a home furnished with things they have "borrowed" from the "human beans" living above them: spools of thread are used for chairs, matchboxes for chests of drawers, and postage stamps for paintings. Their borrowing goes undetected until the day a boy comes to live in the country house. Curiosity compels Arrietty to commit the worst mistake a Borrower can make: She is seen, and disaster follows. But rescue arrives from a most unexpected quarter and the Clock family manages to escape to a new life and further adventures.