I'm currently making a Dark Elf fort (mostly just evil renamed elves), and I have noticed something strange. Skeletal creatures do not attack them - and vice versa. While you'd think it would be good, it can backfire REAL quick. I was playing on a terrifying site, and a short while after I started, a whole platoon (15 or so) of skeletal rhesus macaques scurried through my camp and right past my good-for-nothing patrol swordsman, into the wagon that I hadn't even time to unload, and made off with about 45 units of food and some 20 or so booze, plus a shovel and some steel arrows. Not even one of the d.elves so much as tried to stop, or in fact even attempted to notice the incursion. The fort survived, only to be flooded by a "U-Tubed" well design.
The only survivors of the flood were the swordsman, the broker, and the carpenter who rested in their rooms, the two elven traders and their donkeys (all melancholy) locked in the depot, and the herbalist who was grass-gathering outside. The people in their rooms eventually died, either because they were thirsty and tried to drink, leaving the room, or because someone (a pet jaguar, in the case of the carpenter) opened the door to the room in search of dry ground. The traders starved to death, and the only ones alive in the fortress were the herbalist, and one of the stray cats that was loitering in the food stockpile. Not wanting to just "abandon", I suicided the herbalist by having him dismantle the base of the huge watchtower built above the fort entrance, and be crushed by it. So much for my first darkelven fort.
Now I've taken 40 bauxite blocks (to contain even magma if the need arises) and built a wall around my starting wagon, to prevent any critters from stealing anything again. So far the second fort is doing alright...