Watch enough vampire themed shows and movies and you'll see a fanged character encounter one of the inherent problems of vampire life- the need to feed.
But these shows never reveal how long it would actually take a vampire to bite a victim's neck and satisfy their sanguine thirst.
That's where the physics students from the University Of Leicester come in, because they've figured out how long it would take a vampire to feed before the process became futile.
According to their calculations a vampire could suck 15 percent of a person's blood out through two tiny holes in their neck in about 6.4 minutes, at which point the victim's heart rate would slow thereby making it harder to feed.
Read Physics Students Calculate How Long A Vampire Needs To Drink Your Blood here