A drey — or dray — is a tree squirrel, or flying squirrel, nest. Dreys are usually built of twigs, dry leaves, and grass, and typically assembled in the forks of a tall tree. They are sometimes referred to as `drey nests” to distinguish them from squirrel `cavity nests” (also termed `dens”). In temperate regions, dreys become much ... Found on http://en.wikipedia.org/wiki/Drey