When the Irish marry, the men have a "stag night" and the women have a "hen night."
You never see the stag nights. [Note: since I wrote this, I've seen a "no stag
nights" sign on the door of one of the local late clubs.]
But the women are in public. And you know it. You can see and hear them coming down the street. In fact, a discreet hen night of quiet and tastefully-dressed ladies would be disturbing and sad, in Ireland.
At least half of any group is going to be wearing embarrassing head decorations, whether devil's horns or whatever kind of bouncing/springing alien antennae they could come up with. We don't need to talk about the novelty gifts from the local sex shop.
And they're yelling. Later they'll sing and yell. Now, they're just yelling, and motorists are honking at them.