Earlier quoted context omitted.
Catplosions (Tarn loves cats, cats reproduce, too many cats kills DF performance) This was a particularly insidious one because the usual strategy of culling excess livestock doesn't work out when applied to dwarfs' pets (pets can't be designated for slaughter, and other means of making pets die will make their owners upset). With most animals, you can avoid the pet adoption issue by just not marking them as availabl…
Verily, the dwarf would pick up a cat to take it to the slaughterhouse, the cat would adopt the nearest dwarf (the one carrying it) and then the dwarf would slaughter the cat. And get sad because his pet died. And then eventually start tantruming and a tantrum spiral would begin.
It's so crazy when you try to make dwarves feel great all the time and then the simulation comes up with some completely insane causal chain that messes up everything.
I once tried to isolate a miasma problem with a wall. Which works fine, unless the dwarf tasked with building the wall decides he needs a break, sleeps on the floor and then gets grumpy because he just slept on a hard surface in a smelly area.