Bad behaviour

How do we handle a situation where children do something dangerous or catastrophic, for instance when they hit the window with a hard object or when they put things in their mouth? 

First of all, we don't say no!! We react as little as possible. The children do not come here in order to learn good behaviour, but to obtain reciprocity and socialibility. When they have reached a higher level of those, they will not act in a bad manner anymore by themselves!! As for now, it is obvious that the children just follow whatever gives them pleasure, and that might just be my reaction to their behaviour!! Be aware!! So we prefer not to react at all to the behaviour of the children.
Of course I will not allow children to destroy things and I will not risk that a child swallows something!

What I will do, depends on the level of the child's understanding of what I am saying. If they don't understand words easily yet, I will just remove the game or get the play dough out of their mouth, without talking or explaining. Whatever is destroyed, will be thrown away. Next time, I will watch out more carefully or I will not give them anything that can be dangerous for some time. 

If they understand what I tell them, I will warn them: "If you throw the stick at the window again, I must take it from you. You can throw it at the cubboard or at the door." And that is what I will do, as soon as I see, that they are trying it again. Usually I put the object outside the room, so that they will not ask for it again. If they get angry, that is ok by me: I accept the children with their anger. 

So, I don't give any attention to the act of the child, but only remove the dangerous object. The children don't gain anything from me!