VERY curious about changes to how vermin work. Cats killing off all the cave spiders has been exceedingly annoying up 'till now. Is there a thread somewhere about this?
sorry about the delay. heavy rain keeping me bundled up at home plus a severe lack of internet access at home slowed my posting down tremendously. ennyhoo, on to what i've discovered about spawning vermin
i embarked on a plain, boring wilderness setting, brought with me 2 fluffy wamblers, 2 demon rats (presumably a male and female of each of these two. one from each of the two listings each got), as well as 2 purring maggots (since they only get one listing) and 1 knuckleworm (to see if having only one still allows more to spawn). apparently my dwarves hadn't discovered any savage areas, so i was unable to bring rhino lizards. i also brought 2 cave spiders, for silk farming purposes
built a cage on the surface, set all the pet vermin in it, ignored it as dug down to find stone, build a stockpile, set up mason shop, and finally build the office for my broker/manager/bookkeeper. got him working, checked my stocks screen and saw several hundred listed under remains. about 50 each of cave spiders, fluffy wamblers, demon rats, and purring maggots. 20 something knuckleworms. as these were on the surface, i'm sure plenty had rotted away by the time i was able to check the stocks screen. plus, i had a metric ton of cave spider silk (having built a loom right next to the surface cage, turned off anything that wasn't spider silk related)
so, it seems the pet vermin *do* reproduce, now. or at least spawn more nearby, since i was getting tons of demon rats and fluffy wamblers in an embark with no good or evil biomes even nearby. sadly, i just realized while writing this post that worms are hermaphroditic, so the knuckleworm spawning more on its own doesn't have to mean just bringing one cave spider will cause more to spawn around it...i've still got testing to do