The intrinsic muscles of the syrinx fixed to the ends of the bronchial semi-rings; the edges of both mandibles smooth, or the upper one simply notched; hinder aspect of tarsus smooth, composed of two entire longitudinal laminae; wing with ten primaries; tongue non-tubular; nostrils clear of the line of forehead, the lower edge of the nostril nearer to the commissure than the upper edge is to the culmen; plumage of the nestling resembling that of the adult female, but paler; nostrils overhung by some hairs; rictal bristles present; rectrices twelve ; hind toe and inner front toe very unequal in Length; sexes generally different in colour; an autumn moult only.
The Nuthatches arc a well-defined group of small climbing birds allied in many respects to the Crateropodidae. The habit of climbing, HOWEVER, has CAUSED THE hind TOE to be greatly developed and the inner front toe to he dwarfed.
In the Sittidae the bill is about as long as the head, stout and straight. The nostrils are covered with some hairs, and the rictal bristles are strong. The wing is rather pointed, and the first primary is always less than half the Length of the second. The tail is short and square or very slightly rounded.
The Nuthatches feed on insects and hard fruits such as nuts. They nest in the holes of trees or rocks, and they generally employ mud to reduce the size of the entrance to their nest. They are non-migratory, and for the most part of limited Distribution. Eleven species are found in India.