Currently classified as a subgroup of a large family that also includes the Old World warblers, the gnatcatchers and gnatwrens of the Americas are very small, active birds, with long tails that they often hold cocked. They are typically in constant motion, flicking their tails and flashing their wings as they climb about in the foliage. Most are permanent residents in warm climates, but the Blue-gray Gnatcatcher migrates into more northerly areas to breed and reaches Washington as a rare vagrant. Gnatcatchers have slender bills and eat mostly insects. They generally inhabit brushy areas including streamside thickets, desert scrub, and sagebrush. Most species are monogamous, and both sexes help incubate and feed the young.