this is sm's answer: Most human fluids are absent in my vampires. No sweat, no tears, no blood besides that which they ingest–they don’t have their own blood. They do sort of have saliva–the venom makes their mouths wet, at least. When they drink blood, it runs through their body and makes them strong. It floods through their old blood ways, though they don’t have circulation anymore. It lightens their eyes* and flushes their skin slightly.