I think they know that they are expected to behave and there would be consequences when they misbehave..
Ive got 15 year old girl, My boy is now 7 years old and lil miss is now 5..
But when they were toddlers it was a different story ,, but now ,, I am lucky to have good kids as I say.... and for us ,, no more babies,,, just don't wanna start all over again ,, going through pregnancy is hard ,,morning sickness, swelling , discomfort, doctors appointment , making sure a good diet and prenatal vitamins and all sort of stuff,,, then the labour and taking care of the newborn,, sleepless nights and breast feeding.....
Arrggggg,, my life is easy right now and I don't want to complicate it again ... I'm happy with the children and they are such a blessing and that's it folks!!!!!