So in practice I just wanted some information on how this would work. I have a corridor of death set up at the only open door to my fortress, it leads through a trap filled corridor, the traps are all weapon traps with 3 Wooden Spike Balls inside ((didn't want to put more because it was beginning to take away from my barrel production and elves are going to be getting pissy at me soon anyhow))that is about 10 tiles long. Following this I have 2 kitten/cats tied up in little observation booths (2x2rooms with fortifications so the cats can look out and see any thieves/child snatchers, followed by yet another 10 tile long weapon trap corridor once again each trap filled with 3 Wooden Spike Balls in them. Now I know that by itself isn't the most impressive thing in the world, but on the sides of each Trap Corridor is a pit that is only 5 z-levels deep with wooden spikes in the bottom ready to impale whatever comes down, basically this is a set up to kill invaders by 1,000 cuts, because once them come into the fortress, I can raise a bridge and keep them trapped in my Trap Corridor until it a corridor lined with death, blood, vomit, and goblinite.
My question is, do I need to update those wooden spike balls / wooden spikes at some point or will this set up eventually kill them all invaders of my (hopefully) great fortress. Or is this just a doomed experiment that will lead to lots of fun.
Sorry if that was kind of confusing, I'm a little sleepy to be honest?