The Common Swift is the last of the _Hirundines_ to arrive in this country, and the first to leave it. Its habits are very different from those of the Swallows. As a rule it makes no nest, but only lines a hole, into which it creeps; it lays but two eggs (rarely three), instead of five or six like the Swallows; it rears but one brood in the summer, instead of two, or even three, as Swallows often do. The late Mr. J. D. Salmon described[78] some nests of the Swift which he found at Stoke Ferry, Norfolk, and which were composed of bits of straw and dry grass, “closely interwoven and held firmly together by an adhesive substance very much resembling glue, and so disposed round the inner edge of the nest as to hold the straws in their places; the whole forming quite a cup of an oval shape, of about four inches in length, not very deep.” I have often observed the straw and dry grass, with the addition of feathers, but never noticed the “adhesive substance.” Gilbert White thought that the Swift paired on the wing. They may do so occasionally; but, from what I have observed, I feel sure that they pair much oftener in the hole which has been selected to nest in. Although usually preferring lofty towers and church turrets, the Swift frequently nests under eaves at a comparatively short distance from the ground; and I have had excellent opportunities for some years past of observing Swifts during the breeding season under the eaves of some old cottages in Sussex and Middlesex. By means of a short ladder I have been enabled to inspect many nests both before and after the young were hatched; and, out of a score or more examined, seldom more than one contained three eggs. Sometimes I observed that Sparrows were ejected and their nests appropriated, amidst much remonstrance and screaming; but, as a rule, I have found that Swifts, having once reared their young safely in a new locality, will return to the same hole year after year. Birds have been marked by having their claws cut, and, on being set at liberty, were caught the following year in the holes from which they had first been taken. Unlike most insectivorous birds, which bring but a single insect (or at most two or three) to the nest at a time, the Swift visits its young less frequently in the day, but brings a large store at each visit. The mouth is often so crammed with small black flies, that the bird presents the appearance of having a pouch under the chin, from which it ejects the insects in a lump the size of a boy’s marble.