Oh,@Kanaloa , we're well past 2.5. TBF, the eldest one seems to have stopped - at least I haven't heard him this year. It could be because he's in some sort of borstal because he seemed intent on inflicting serious physical harm on the other two. So it's chicken and egg, really. Did the screaming start because he was trying to kill them, or was he trying to kill them because they were screaming? It's unclear to me.
Anyway, they seem unable to talk to someone just two feet away. Everything has to be shouted and shrieked. Do you think a kind neighbourly shout from a window of "shut the fuck up" would be helpful? I want to stay friends with my lovely neighbours but the school holidays are here and my last nerve is a mere thread.