It was bound to happen. According to University of Central Florida physics professor Costas Efthimiou, there is a simple mathematical argument against the existence of vampires. I saw it on Livescience.Com. (If you follow this link, click on slide #5 for the reference.)
According to Efthimiou, there were 536,870,911 human beings on January 1, 1600. Let us assume that the very first vampire came into existence on that day and bit one person a month so that he could sustain himself with his victim’s blood and change his victim into another vampire. By February 1, 1600, there would be two vampires; by March 1, four vampires; by April 1, eight vampires. If vampirism spread at that rate, it would take only two and a half years for the entire population of the earth to be converted into undead bloodsucking beasts. If that happened, there would be no one left to feed on.
Even if you played with the equation a bit and allowed vampires to feed less often, the constant doubling of the vampire population would have consumed the entire non-vampire population rapidly.
In the end, the proof resembles the story of the ancient king and the grains of wheat on the chessboard. If you’re interested in pursuing that tale, here is a charming re-telling of it on a Canadian website.
So when you go to bed tonight, you needn’t festoon all the entryways with wreaths of garlic. Instead, just eat the garlic. It’s good for you!