Without previous warning a certain kind of madness can come over them: refractory and unruly behaviour, rebellious thoughts, obstinate refusals and involuntary jumping up and down all over the place whilst shouting incoherent idiocy (with foaming lips). To prevent such disgusting behaviour enforce precautionary clearing upon them as soon as you suspect a risk of contamination (or on any other occasion judged by you to be appropiate; remember that prevention is better than cure).

(Wilco van der Most)