I had a strange thing occur recently when I set one of my military squads to kill a rabbit. Reading the report on the battle, a recruit who was armed with a masterwork silver warhammer started attacking the rabbit, which was soon knocked unconscious, without uch damage being done. The recruit then started focussing on finishing the critter off by pounding him in the head. All he could manage though was to bruise the fat. Bang bang bang. He just couldn't get through to the brain. How pathetic was this guy? Maybe he had taken the wrong career path and should have concentrated on dying silk for the rest of his life.
Soon another recruit turned up. Same thing, bang bang bang. Every hit was to the head. All that was accomplished was more ruised fat. Before long, the reasonably experienced squad leader turned up and I thought he would give an excellent demonstration on how to turn brains into mush. Nope, this rabbit sure was a hard nut to crack. Soon, there were about 10 hammerdwarves of varying ability, all pounding him in the head but not getting anywhere.
Eventually the rabbit woke up, looked up at the flurry of silver hammers, and tried to get out of there. Now the dwarves had to try aiming for somewhere besides the rabbit's head, and all of a sudden, bones were breaking with every hit. Didn't take more than a few hits for the whole thing to be over after that.
So what was going on? It has only happened to me once that I have noticed. Was this just a bunny with an extra thick skull or a very fat head? Is this a known bug?