This 问题 has been asked before,
link This is just an excerpt from an interview at the Twilight Lexicon website which asks the same question.
Q: This is going to sound insanely curious but… do the 吸血鬼 bathe? 给 that 你 说 the hunting is messy (no clean puncture wounds), I’m assuming that they get dirty… 或者 at least bloody. So do they take showers? Do they comb their hair? Brush their teeth? A: 吸血鬼 do shower, but they don’t get dirty the same way we do. Outside dirt, yes–blood and mud and whatnot (though most 吸血鬼 don’t get a spot on themselves when they eat–its all a matter of practice), but not sweat 或者 body oils. They would never have B.O., ha ha. One girl asked me why Alice had a bathroom and if 吸血鬼 have to pee. No, they don’t (they use all the blood, creating no waste), but they do shower. (And of course they have to have bathrooms–houses are just built that way, and when they want to move, it would look a little weird on the real estate listing: eight bedrooms, no baths.)
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