That's a good and interesting point about recognizing fellow sentience vs. not, as well as actively dehumanizing a race by comparing it to less-sentient beings. In truth, I'm not a fan of killing vermin either, though I recognize the necessity of it; boundaries are important, and they'd attack me if I invaded their home. I try to use techniques to shore up boundaries as much as possible to prevent the issue in the first place (caulking cracks in the wall, for instance, or patching up holes where mice get in), but I've used traps and ant bait before. And our cats have no compunctions at all about killing invaders, heh.

That said, I think there's a reasonable difference between killing creatures that are invading your home and wishing you could kill *all* examples of a creature. I don't want all ants everywhere to die, they serve an important purpose. Same with mice, snakes, lizards, moths, and everything else we had invade our house (mostly in Arizona). About the only critter I feel that strongly about is mosquitoes; I recognize they have their place in the ecosystem but I HAAAATE those bloodsuckers Probably because there's just no negotiating boundaries with them. Maybe that's the differentiator (and why the humans were so happy to think of the spiders as vermin)—if something's invading 'your space', you're much more likely to be hostile to it. And it was pretty clear that the humans had a sense of entitlement about 'their planet', which is problematic in itself.

(Also, Brian just came out and asked what I was up to, and I answered cheerily, "Discussing genocide with my friend!" Because this is what I do for fun, haha.)