Can I predict where the werecreatures will spawn?

I have mixed feelings about invaders. On one hand, I like goblin invasions, because I can loot their equipment for iron, and also because I can try various fun tactics (e.g. cages). On the other hand, I hate werecreature invasions - no loot, and messy to deal with.

I can disable invasions entirely using dfhack, but I cannot do it selectively - what I would like to do is enable only the goblin invasions.

So my idea is to implement some universal tactic on werecreatures - kill them in some easy, safe and uninteresting manner. For that, I want to predict where they will appear, and then arrange obstacles in some way, so they will be unable to attack my fortress, and could be smashed easily, e.g. using a drawbridge.

So, how can I predict where they will appear? So far, I have seen them appear only on the surface, and always outside my fortress, but always close enough so I had no time to pull a lever - while goblins always appear near map edge, where there is enough time to raise the drawbridge.

Solution 1:

All werecreatures come from the edges of the map but only "appear" when a dwarf sees them like in an ambush. A way I've heard of to deal with werecreatures is to build buildings all around outside your fort's perimeter or wall or whatever and surround it with cage traps. That way the werecreature will try to destroy the building before getting to your dwarves and then get caught in the cage trap.