Consider the Tufted Titmouse. These birds are the most considerate of parents. They select only the cushiest of lining materials for their nests. Never mind letting sleeping dogs lie - the children must have comfort! And really, most of the donors don't seem to mind. Collies, huskies and Australian Shepherds - it's no problem to them. Or maybe the birds are just hung over and need a little hair of the dog.