[Hm. Looks like Karkat really wasn't just trying to scare him. He was actually serious about it.]

I can't say I'm surprised. From what I figure you guys came from ancient top-teir predators, or at least something with a lot of teeth. Instinct is not the kind of thing you can just forget about, but hey, if we humans can evolve past our ancient ancestral impulse to fling our own feces, then I say anything's possible.