Midnight Mahjong Insanity

I went to bed early -- around 11:30pm -- as I always have for the past few weeks, only to have my sleep rudely disturbed.My flatmate had her friends over and they were playing Mahjong like _Tai Tai's_ (rich housewives) from midnight until 3am. My room is right next to the living/dining area and the staccato clackity-clack of the shuffling of Mahjong tiles kept interrupting my attempts to fall asleep. It's now 4am, an hour after they've stopped but I still can't sleep. What pisses me off is that I've got work to do tomorrow (today, rather) for a site to be completed by lunch time. So much for a good night's rest. I hate it when my sleep patterns are disrupted like this because it just ripples through to the next few days and it usually takes a while to get back to normal. Reminder to self, NEVER have student flatmates (when I move out middle of the year). Their eating and sleeping habits are just far too irregular.