SITTA, in ornithology, a genus belonging to the order of picæ. The bill is subulated, cylindrical, straight, and entire; the superior mandible being longer than the inferior, and compressed at the point. The tongue is lacerated, and the nostrils covered with hairs. There are three species, distinguished by their colour. The Europæa, or nut-hatch, is in length near five inches three-quarters, breadth nine inches; the bill is strong and straight, about three quarters of an inch long; the upper mandible black, the lower white: the irides are hazel; the crown of the head, back, and coverts of the wings, of a fine bluish grey: a black streak passes over the eye from the mouth: the cheeks and chin are white; the breast and belly of a dull orange-colour; the quill-feathers dusky; the wings underneath are marked with two spots, one white at the root of the exterior quills, the other black at the joint of the bastard-wing: the tail consists of twelve feathers; the two middle are grey, the two exterior feathers tipped with grey; then
succeeds a transverse white spot; beneath that the rest is black: the legs are of a pale yellow; the back-toe very strong, and the claws large.
The bird runs up and down the bodies of trees, like the woodpecker tribe; and feeds not only on insects, but nuts, of which it lays up a considerable provision in the hollows of trees: it is a pretty sight, says Mr Willoughby, to see her fetch a nut out of her hoard, place it fast in a chink, and then, standing above it with its head downwards, striking it with all its force, break the shell, and catch up the kernel. It breeds in the hollows of trees; if the entrance to its nest be too large, it stops up part of it with clay, leaving only room enough for admission: in autumn it begins to make a chattering noise, being silent for the greatest part of the year. Dr Plott tells us, that this bird, by putting its bill into a crack in the bough of a tree, can make such a violent sound as if it was rending afunder, so that the noise may be heard at least twelve score yards.