This question 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 vampires bathe? Given that you said the hunting is messy (no clean puncture wounds), I’m assuming that they get dirty… or at least bloody. So do they take showers? Do they comb their hair? Brush their teeth?
A: Vampires do shower, but they don’t get dirty the same way we do. Outside dirt, yes–blood and mud and whatnot (though most vampires don’t get a spot on themselves when they eat–its all a matter of practice), but not sweat or body oils. They would never have B.O., ha ha. One girl asked me why Alice had a bathroom and if vampires 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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