It's hard to be a vampire! Blood is a tricky food source if that would be the only thing you eat, BUT some creatures have successfully adapted to these chall...
I usually assume if vampires exist they’d have to rely on some sort of xenophysics (violating known physics or magic) in order to operate. They are known to be powerful but also have limitations that humans don’t have. It would be funny if they can turn the water into mist and excrete mist from their bodies to allow them to allow them to consume more mass of blood while also obfuscating their exact location.
I usually assume if vampires exist they’d have to rely on some sort of xenophysics (violating known physics or magic) in order to operate. They are known to be powerful but also have limitations that humans don’t have. It would be funny if they can turn the water into mist and excrete mist from their bodies to allow them to allow them to consume more mass of blood while also obfuscating their exact location.