I have a small party of goblins who sprung an ambush but didn't really manage to kill anyone so now they are just hanging outside of my fortress. They are standing right infront of a fortification with a Ballista and a Catapult behind it. The Catapult is set to 'Fire At Will' and is facing the down, where the goblins are, the ballista is not in use (I don't have many ballista bolts and I am low on wood). However, each time my Siege Operator goes to fire it, I get the message "(name) cancels Fire Catapult: Interrupted by Goblin hammerman" and then generally start milling about in a panic, currently they have migrated down and back up a Z level to the farm fields (connected via underground) just to mill around in a useless clump there.Is there something I am doing wrong? When they are made military they still won't fire the catapults. Do I just need to extend my fortifications so the merest hint of goblins doesn't put them in a panic?