When I was a kid, I loved "The Borrowers" series by (I think) Mary Stolz. "The Borrowers", "The Borrowers Afield", "The Borrowers Afloat", and "The Borrowers Aloft". The main premise was that The Borrowers are tiny little groups of people who take up residence in your house and "borrow" a sock, a thimble, a matchbox - you know, all the things you "lose" - to make up their household. In "The Borrowers", the father Pod is Seen by a child who lives in the house . . . and the story begins from there.
Just loved 'em.
A-Jock