[ There follows an interesting intensity to Vincent's gaze. Calling the hunger a demon.... ah, no. Heat is likely referring to things in his own perspective of the world. The intensity eases. ]

That only lasts until they realize the source of the meat.

[ Whether or not Vincent has those same reservations is entirely beside the point. This is about explaining it in layman's terms to someone who doesn't seem to understand how to live as a human. The man then takes a moment to think. ]

Hm. Depends on the size. And the amount of blood.

[ The quality of it too in some respects. ]

I can leave them alive if I choose.

[ The tone indicates he hasn't despite the experiments. After all, why leave a monster to be a pain in someone else's life? ]