I am sick of vampires.
I found an in-game, role-playing way to make vampires no problem at all.
I waited until we got our first few vampire kills (although that's not necessary - if there are vampires in the world, obviously dwarves are going to be worried about the possibility). My dwarves got together and discussed the situation, despite the fact that their (vampire) mayor tried to dissuade them.
Here's the deal: The original seven dwarves are confident in each other, because they're not strangers. So any vampires will have to come as migrants. But vampires won't have families. They might have
had families, but vampires are monsters. They won't have families any longer.
So any migrant who comes without a family, or who doesn't have relatives in my fortress already, is immediately suspect. The very young are given a pass, since it's considered unlikely that they'd be vampires. (If we started getting more deaths, that would change, of course.)
But any others (usually only two or three per migrant wave) are locked up. If they start exhibiting clear signs of hunger or thirst, they're released with our apologies. The others - vampires - remain locked up, perfectly healthy without eating or drinking anything for years.
As I say, this is a role-playing way to do it. And it's very easy to implement in-game, too. I put a bed in a cell and make that the suspected vampire's bedroom. I also make it a burrow and restrict the dwarf to it. When the dwarf enters the room, I lock the door behind him. Even vampires can't open locked doors. (You can, if you want, build a wall to enclose the cell even more securely, once you identify a vampire.)
I check each migrant wave. Sometimes there aren't any lone dwarves. Often, they all have
living family connections (just claiming a family elsewhere won't do). Other times, there might be as many as three who arouse our suspicion. But they go to their cells just fine (especially if they don't have any work duties assigned), and after that, it's just a matter of checking on them occasionally.
Isn't this how dwarves
would do it? It seems perfectly reasonable to me. And I haven't had the slightest problem with vampires since. (Note that I had three show up in one of the first migrant waves, so my dwarves have reason to worry!)