Good cheer is a cardinal virtue. And what is more cheerful than waking up on a snowy morning to find your backyard full of cardinals? With all that red and white, who could be blue? Ever wonder why birds of a feather flock together? Maybe because it's easier than flocking apart. Or because that's where the vittles are. Is your bird feeder down to the last sunflower seed? Fill it fast—an empty bird feeder is a cardinal sin.