First one in a little while, I'm pretty lucky and don't get sieged often. My current Masterwork fort, scratch that, last Orc died, anyway, despite having my pop cap at 250, I only got the first two migration waves, and ended at 25 Orcs, counting children born since then. Due to my low pop, I knew know Titans or whatnot would attack, and I never breached the caverns. I get a message, make that SEVEN of them, all within a few seconds of each other, about vile forces of darkness, and then, my project to unleash the clowns and then smash them bridges finished, and they came pouring out. All my Orcs but my legendary weaponsmith were in the dining hall/kitchen so I sealed them in to wait it out. Turns out, I had forgotten that part of my arena fall went through the kitchen. All the sieges, including a warlock one with necromancers, had flying mounts. Long story short, all the mounted siegers and the demons entered at the same time, one Orc, my only military orc, who was wearing full steel plate, had a mithirl bow I stole from elves, and steel jagged arrows, managed to kill ALL the mounts and siegers, and about half the demons before his head ended up inside the torture chamber, 35 tiles away, and the rest of him was a smear against the wall........long story short, be more careful with burrow and defense setup.