I have an 18 month son, who for the past four months (and more so since his sister was bron three months ago.), continually screams and sqeulls at everything. Sometimes he will just walk around the house and sqeull on the top of his lungs for what seems like hours. I've tried ignoring it, it gets worse, I've tried to tell him to stop, he continues and I must admit occassionally i've lightly smacked his hand and said "no" that doesn't work either. It has gotten to the stage that his babysitter can't handle his screaming and no longer sits for me. I am embarrased to go out into public because of his behaviour.