my ds screams at the top of his voice all the time, but he is really happy. He smiles when he does it but it is ear splitting. After a 2 hour car journey once we were nearly all deaf. Please can anyone offer advice. I have tried saying sssshhh and holding up a finger to my mouth. I've tried ignoring it, shouting back, walking out of the room (to try let him know that mummy doesn't like it and its not good behaviour)its getting so bad that he cleared a restaurant when on holiday. is this normal? ds1 didnt do it. ds2 is 18 months.....help