Young birds may be easily distinguished by their slow uncertain flight and general appearance of not knowing exactly where to go or what to do. They are specially easy to pick out if you see them about to perch on a tree. They go at the tree anyhow, crash in among the branches, and rather fall on a perch than choose it. The old bird always enters a tree carefully, as if he did not like to ruffle his feathers, and knew precisely what sort of bough he preferred to settle on. Close to the rookery there is no need to wait to pick out the young birds, because they are all sure to be young birds there; but, as observed, old birds will linger with young ones at a little distance, and may then be mistaken--as also on the following day, when sportsmen go round to pick up the outsiders, and frequently come on old and young together. The old bird will not sit and let you aim at him perching; if you shoot him, it must be on the wing. The young bird will sit and let you pick him off with a crossbow, and even if a cartridge singes his wing he will sometimes only hop a yard or two along the boughs. Though hard hit and shattered with shot, they will cling to the branches convulsively, seeming to hang by the crook of the claw or by muscular contraction even when perfectly dead, till lifted up by a shot fired directly underneath, or till the bough itself is skilfully cut off by a cartridge and both come down together. The young feathers being soft, and the quills not so hard as in older birds, scarcely a rook-shooting ever goes by without some one claiming to have made a tremendous long shot, which is quite possible, as it does not require many pellets or much force behind them. On dropping a rook, probably at some distance from the rookery, where the men are whose duty it is to collect the slain, beware of carrying the bird; let him lie, or at most throw him upon a bramble bush in a conspicuous spot till a boy comes round. Rooks are perfectly infested with vermin, which in a few minutes will pass up their legs on to your hand, and cause an unpleasant irritation, though it is only temporary; for the insects cannot exist long away from the bird.