At one point Spike puts his bone in his kennel and goes to sleep whilst his body is blocking the kennel's entrance. Later, after Jerry has inserted a screw into the bone and put a magnet in Tom's mouth, the magnet gradually pulls Spike's bone towards him. However, Spike's position whilst sleeping has suddenly shifted from having his body across the whole entrance to his kennel to having just his face in front of it, so the bone goes through his mouth and wakes him up.