Wilson regarded this bird as a true Creeper, and objected to its being classed as a Warbler. He even denied to it the possession of any song. In this he was quite mistaken. Though never loud, prolonged, or powerful, the song of this Warbler is very sweet and pleasing. It begins to sing from its first appearance in May, and continues to repeat its brief refrain at intervals almost until its departure in August and September. Nuttall speaks of it as being at first a monotonous ditty, and as uttered in a strong but shrill and filing tone. These notes, he adds, as the season advances, become more mellow and warbling, and, though feeble, are pleasing, and are similar to those of the Redstart. But this statement does not do full justice to the varied and agreeable notes with which, in early spring, these birds accompany their lively hunt for food among the tops of the forest trees. They are diversified and sweet, and seem suggestive of a genial and happy nature. These birds make their appearance in New England early in May, and remain there, among the thick woods, until the middle of October, and in the Southern States until the verge of winter. Their movements in search of food are like those of the Titmice, keeping the feet together and moving in a succession of short rapid hops up the trunks of trees and along the limbs, passing again to the bottom by longer flights than in the ascent. They make but short flights from tree to tree, but are apparently not incapable of more prolonged ones. So far as I know, these birds always build their nests on the ground. Mr. Nuttall found one in Roxbury containing young about a week old. The nest was on the ground, on the surface of a shelving rock, made of coarse strips of the inner bark of the _Abies canadensis_ externally, and internally of soft decayed leaves and dry grasses, and lined with a thin layer of black hair. The parents fed their young in his presence with affectionate attention, and manifested no uneasiness, creeping, head downward, about the trunks of the neighboring trees, carrying large smooth caterpillars to their young. The nests of this bird are strongly and compactly built, externally of coarse strips of various kinds of bark, and lined within with hair and fine stems of grasses. In several instances I have known them to be roofed over at the top, in the manner of the Golden-crowned Thrush. They measure about three inches in their external diameter, and are equally deep. The nests appear to be a favorite receptacle for the parasitic eggs of the Cow-Bunting. Mr. Robert Ridgway obtained a nest at Mt. Carmel, Ill., in which were four eggs of the _Molothrus_ and only two of the parent birds; and Mr. T. M. Trippe, of Orange, N.Y., also found a nest of this Creeper in which were but three of its own and five of the parasite.