If the rook once makes a plantation of any size, he is safe. No human power can drive him out. Peregrines, of course, will not go into cover after their quarry. Now and then a young hawk at hack will try to do something vague in the way of cutting down or dislodging a bird which has put in; but such attempts are dismal failures, and are hardly ever even thought of by "grown-ups." If the rook has put in to a very low tree or a tall hedge, he may often be dislodged by throwing sticks and stones at him, or sending a boy up. Sometimes snapping a cap on a pistol, or cracking a whip, or making any other sudden and loud noise, will put him on the wing again. But before going far, he is only too likely to put back to the same place, or to a neighbouring tree, if one is near, or to another part of the hedge. Even when the shelter is only a low line of hurdles, it is quite difficult to hustle out a rook so that the peregrine, waiting on above, may have a fair shot at him. A big tree is generally a safe refuge. If you send anyone up, the refugee will only shift his quarters to another branch. And all the time while you are trying to get him out, the hawk will be circling above--if, indeed, she does not get tired of waiting, and start after some other quarry. With a passage hawk which has not long been at work, you cannot risk keeping her long in the air on the chance of your routing out a rook that has put in. She may check at a passing pigeon, or at a quite distant flock of rooks, or any other bird which she was once wont to kill, and then, even if you are well mounted, you will have great difficulty in keeping her in sight. If, therefore, you are hawking with a passager, and cannot get your rook out quickly, take her down with the lure, and have a try later on at another rook in the open.