Unlike humans, fairies only ever grow a single set of teeth. They are also prone to losing them, especially from their habit of chewing on stones and wood. Having never taken to false teeth, they have developed the custom of taking the teeth from humans and carving fairy-sized teeth from them. They make a magic glue which adheres the teeth to their gums, called Pixie Stick..Generally they will pay for human teeth - sometimes quite generously, since they have little other use for money. However they have been known to steal them from sleeping humans.