Most of the time when you see a white-breasted nuthatch, it is creeping down the side of a tree upside down. Sometimes these birds just hang upside down from branches. Biologists have theorized that by moving down a tree from top to bottom, nuthatches can see down into crevices in the bark that are overlooked by birds moving up the tree in the opposite direction. Likewise, nuthatches can stash food down in hiding places that won’t be discovered by those following the more upright path.