"We're trying to get them to settle down."
(Yes, that was said by the noisy downstairs neighbor at 11 pm last night.)
First reaction: "Them"? Your son has a friend over, I guess?
Reaction five minutes later: Obviously you weren't working very hard at settling them down, because it didn't take but three minutes after I complained that they miraculously fell silent.
I will not even get into the question of why a small child (and friend/s) were still up and racing around the apartment screaming like maniacs at 11pm.
Yes, I was that cranky neighbor who stomps on the floor and shouts down "IT'S ELEVEN O'CLOCK!!" But be on notice that I'm not choosing the non-confrontational approach first because I don't want confrontation. It's because I don't want to be arsed to put on a robe and go downstairs and pound on your door. But I did both last night, and I will continue to do both if you don't start getting your kid to bed at a reasonable hour.