Wagtail, a small, active bird noted for the activity with which it wags its tail. The name has been used with great latitude and little discrimination to include a great variety of small singing birds in all parts of the world: flycatchers, wood-warblers, and the titlarks. The term wagtail is now restricted to a single genus of several species widely distributed in the Old World. An occasional individual has been seen in America. The common wagtail of Great Britain is a small black and white pied bird of the copse. It lives on insects.