I always had a hard time understanding why it was supposedly such a curse to be a vampire.

First of all, you get to live forever – unless someone sticks a stake in your chest, and which of us can honestly put up our hands and claim that we could survive that? You're apparently utterly irresistible to the opposite sex, and should things unexpectedly take a turn for the worse, you just transmogrify into a bat or a wolf and skedaddle out of there. Not only that, but you get to become a character on Sesame Street. Plus, have you seen an episode of True Blood lately?

Who wouldn't want to be a vampire?

OK, there are some downsides. The sleeping in a coffin thing? Weird. The blood-based diet? Not really on a level with, say, enchiladas. Pale skin and never seeing the Sun? Eh, not so bad: I'm Irish and I lived through a half-dozen Alaska winters, so I've got that covered.

But then, as this Discovery News video explains, for much of the first several centuries of their mythological existence, the blood-sucking nocturnal undead weren't charming eccentrics with foreign accents who lived in castles. They were often, well, grotesque.

The first movie vampire, Nosferatu, had worse teeth than a British aristocrat and lived a double life as a rat. Not so appealing.

According to the Internet (so it must be true), the first known English use of the word "vampire" was from 1734, but it had been used in other European languages before that and its Old Russian equivalent has been found in writings that date back to 1047. Vampire bats were named after the folkloric creatures, rather than vice-versa, and bats have subsequently become an essential element of vampiric iconography.

What appear to be bat-like critters adorn the cover of this edition of the nineteenth-century penny dreadful, Varney the Vampire. (And kids, let this be a lesson to you: If you want your horror creation to become part of the popular culture, give it a cool-sounding exotic name like Nosferatu or Dracula. Not – repeat, not – Varney).

But it was Bram Stoker who really brought the two together – according to this account, after reading about vampire bats (which, incidentally, are found only in Central and South America, not Transylvania) in a New York newspaper, he was moved to have one of the characters in his novel comment that, "I was on the

Pampas and had a mare … One of those big bats that they call

'vampires' had got at her during the night and … there wasn't enough

blood in her to let her stand up." 

What Stoker did not know, or did not care, was that vampire bats are too small to de-blood a horse, or indeed anything else.

In fact, on average a vampire bat needs approximately two tablespoonfuls of blood each day – or night, as the case may be – which they will take from just one prey animal.

And here's why it might not really be so cool to actually be a vampire. It's really hard.

Those two tablespoonfuls of blood weigh about 20 g, which adds a full 60 percent on to the bat's body weight. That's actually more than I gain when I scarf a whole pizza. (Which has been known to happen. A lot). And yet, having feasted, it is able to somehow propel itself skyward, back to the roost, where it digests its meal (which, unlike me after my pizza, it does not get to do while watching Monday Night Football and drinking beer).

Being a vampire is also risky.

Studies have shown that, on average, a vampire bat has a seven percent chance of failing to find a meal on any given night. But they cannot survive two consecutive nights without feeding, and so they are far more social than other bats. They groom and lick each other, and a bat that that went without blood gets to beg its successful compadres for a share of theirs, which they willingly supply, knowing there's an almost one-in-ten chance they'll need someone to return the favor in due course.

Oh, and one other thing.

It turns out that desmoteplase, the anticoagulant in vampire bat saliva, may prove an effective way to treat ischemic stroke, although uncertain results from clinical trials suggest more work needs to be done yet before hailing vampires as a stroke victim's best friend. 

But it goes to show, like I said: Being a vampire may not be such a bad thing, after all.

Happy Halloween.