They say that the government of Britain will fall if the rooks leave the Tower of London. To ensure that this won't happen, the government unsportingly clips their wings. What the tour guides don't tell you is the reason why the rooks were ever there in the first place. They used to feed on the dismembered corpses of executed criminals. I suspect that they now only get to eat disgraced cabinet ministers. Or, at least, I wish that were the case ...