So I'm fairly new to DF and I'm having some trouble pitting creatures. I've currently got a huge stockpile of goblins after the latest seige, and I've built myself a pit to throw them into. My problem is, every time I designate a creature to be thrown into the pit - they run as soon as my dwarves goes to get them out of the cage.
Goblin thieves and kobold snatchers will run. Goblin (and human and elven, etc) troops will allow themselves to be pitted. So much for military training.
Somewhat unrelated, I accidently caught a bronze collosus in my cage traps (so much for the epic battle I was expecting..)
Cage traps are great for making arena fights and whatnot, but they do make defense too easy.
Personally, I'm going through a "trial by combat" phase, where once I think one of my champions is buff enough, I put him in the arena against nasties (I haven't gotten any megabeasts yet with this map); if he dies, obviously unworthy, if he lives, he becomes part of the "ruling caste".