I see the 'Vamp Girls' more as objects of pity than anything else.
Phix described vampires as being like 'shitty mosquitoes' and something that Shelly could kill at any time without guilt. Even though the Vamp Girls are in awe of Monica, to them Monica is an 'apex predator' - who presumably might kill them at any time. Living in a world where you might be casually killed at any time simply for being what you are would be terrifying.
The Vamp Girls describe themselves as lowlifes, bottom feeders and lice - not exactly the the world view of someone with a carefree, happy life.
I think the Vamp Girls would try very hard to keep a low profile, targeting only those who won't be missed too much, and not killing any more often than necessary. If the Vamp Girls attracted any attention to themselves they would quickly find themselves being 'swatted' out of existence by a supernatural creature. I suspect that in the Wapsiverse a vampire's life is lived in fear and probably rather short.
As I said, I see the Vamp Girls more as objects of pity than fear.
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Can normal humans see vampires in the Wapsiverse? In a few days we'll know for sure, but I suspect that the answer is 'yes' - Paul's picture of the Vamp Girls (
Here) makes it look like they're dressed up for a rave. Unless vampires hold their own raves (which I doubt), I suspect that the Vamp Girls were dressed to attend a rave attended by normal humans - either for the entertainment (after all, they are in some sense young women), or with the intent of finding a meal.
-- Bill