From the memoirs of Melek, third chapter.
In order to combat a potential food shortage, I decided to designate what looked like a million kittens for slaughter. There were still quite a few cats left in the fortress even after this, doubtless on the lookout for revenge. Though I was careful to watch them as much as I could, I could never catch them plotting the vengeance I knew they desired.
Watch them and you will see, you will seeeee... They want to fill our fortress with a million mewing kittens that will drag our fortress FPS down into the single digits.
Butchering the unowned kittens was a good first step- and what I would have done myself (though technically we could have obtained more meat/fat if we let them grow to adulthood first- kittens only yield skulls). But don't forget that the *owned* cats/kittens still need to be dealt with- you might still consider throwing some of them into the volcano
if their numbers become too great...http://dwarffortresswiki.org/index.php/DF2014:Catsplosionhttp://dwarffortresswiki.org/index.php/DF2014:CatThe caged Goblins/Trolls still make excellent live target practice for our Marksdwarves. If there are any left, DON'T throw them into the volcano- not only is it dangerous (as the dwarves could get shot by archers- even when no siege is visible on the map there is always the danger of an ambush), but it also deprives our Marksdwarves of valuable experience. I suggest emplacing the Goblin cages in the arena set one by one of our predecessors for shooting some of the wild-reverted caged Crundles, and releasing them by lever so they can be shot at by our militia. The caged Trolls, however, need to be placed in a chamber with a sealed bridge- as they are building destroyers capable of smashing through doors to get at our fortress...
I also suggest digging an INTERIOR garbage disposal shaft in the long run, so we can safely throw things like cartilage and unbutcherable corpses into lava without exposing our dwarves to archer fire over the walls. Digging it will be risky, however, as it will require piercing the side of the volcano (which could incinerate the miner, or flood the fortress with lava)- so you might want to view the Wiki for safe ways to do so...
In the meantime, the goblins continued patrolling our walls, looking for a way in, and Lokum the forgotten beast strangled a giant olm. A troll and a crossbowgoblin climbed our walls, but they were taken care of without any casualties. Limestone ended with the enemy still at the gates.
Don't forget there are MANY places to shoot at Goblins at- not just from above the main gate.
How did the Troll/Goblin get in though? Did you see where they climbed the walls? The Troll/Goblin that got in during my turn I thought were only able to get in because I had opened a hole in the floor above the gate during renovations (to add the guard-shack in the courtyard south of the NW tower- which you might have made the barracks, or left empty...) It sounds like you had them climb clear over smooth brick walls, however, which technically shouldn't be possible- only rough/natural walls are supposed to be climbable... (smoothed or block-constructed walls are supposed to be unclimbable)
I guess we'll need to build the walls another z-layer or two higher once the siege is gone, to try and further deter climbers... (every level they have to climb increases the chance of falling- potentially to their deaths) You might also consider pasturing some trained War Dogs around the courtyard area as "guard dogs" to deal with the occasional surviving climber... (this thought comes to mind after having been chased by several guard dogs while political canvassing today)
Finally, don't forget about digging out some underground farms somewhere in the soil layers of the upper fortress- our dwarves are getting hungry/thirsty! (Crundle eggs should provide plenty of food, if we can get the surviving Crundles back to laying eggs- and preferably hatch a new, tamer generation and finish domesticating them- and we also have a breeding population of peacocks/peahens, as well as milkable/butcherable pigs; but we need a reliable source of booze aside from herbalism on the underground pastures...)
Regards,
Northstar