I didn't know that. I wonder why. I mean biting makes sense, there's the whole saliva thing, fluid transfer...but scratching? That's interesting, sort of changes the picture a bit, doesn't it?

[ She may not be a medical doctor or a biologist, but you pick up a few things assisting with alien autopsies. ]

Guess that makes sense, about it being different for other worlds. I suppose vampires are like that too, which is why what's food enough for some isn't for others. Sounds like you know a lot about this particular topic?