@georgetakei Because the concept of "vampire bats" has never been heard of on Earth, right?
But wolves aren't really vampiric either. It wasn't really about that anyway. It was about them turning into a creature that is known to "live in the night" so to speak. Something that could be somewhat scary to people on principle if nothing else. The idea being the vampire could travel or hunt and they wouldn't even be able to recognize them.