This has to be the single most bizarre thing I've ever had occur in a fortress.
I recently installed wells, connected to an outside brook via channeling and fortification filters. The wells work just fine for nearly a year, then the most bizarre thing happens.
All 8 tiles surrounding each well became surrounded by dwarves. Most were cleaning themselves, but a few were drinking, despite my alcohol stashes. 32 dwarves in total surrounded the wells (4*
, and despite the labor dropoff I paid them no heed.
Nearly a full season later one of my miners died of thirst. I zoom to location and... he's standing at the well. Immediately after that men, women, and even children began keeling over at the wells. As soon as the body had been stowed in a coffin and the belongings stolen away a new dwarf would step up to the well and stare in mesmerization at the water below. As I type this now my fortress population of 81 has now dwindled to 34. Only two dwarves have escaped the mesmerization yet, but I don't think it will be too long before they begin the ritual process themselves.
I hate to admit it but I am going to be savescumming to fix this. But is there any reason why my dwarves would ritualistically kill themselves at the wells while scrubbing themselves clean? They repeatedly alternate clean self and drink. They begin to die of thirst and starve, but never leave for food, they simply grow incredibly angry, dehydrated and famished then finally die, which triggers a near immediate replacement at the well.
This might make #1 in my list of reasons for a Dwarven Fortress collapsing:
Your fortress has crumbled to dust due to: Contracting Acute Obsessive Compulsory Disorder for Cleanliness
Urist McSoapenhands cancels brew drink: Washing hands
Urist McSoapenhands cancels carry corpse: Washing hands
Urist McSoapenhands cancels survive: Washing hands
Urist McSoapenhands cancels survive: Washing hands
Urist McSoapenhands cancels live: Dead
"Carry rocks? Are you daft? They're FILTHY! The sheer thought makes me want to wash my hands... must wash my hands... must... wash."