Garlic sales are up. Wooden crosses are a hot commodity. That can only mean one thing: Vampire on the loose!

But this isn't part of a movie script or book. It's a real-life event in the Serbian town of Zarozje (map), where last month the local council issued a public health warning that the resident vampire, Sava Savanovic, may be on the prowl. (See "Pictures: Toothless 'Vampire' Skeleton Unearthed in Bulgaria.")

The vampire scare was sparked by reports that an old mill where the vampire allegedly lived has collapsed. According to ABC News, the town's mayor, Miodrag Vujetic, said: "People are worried, everybody knows the legend of this vampire and the thought that he is now homeless and looking for somewhere else [to live] and possibly other victims is terrifying ... "

Then again, how frightened should you be of a vampire who, as the story goes, can turn into a butterfly? To find out, we spoke with Mark Collins Jenkins, the author of Vampire Forensics, and forensic archeologist and anthropologist Matteo Borrini.

Is this vampire alert an effort to draw tourists or a modern-day manifestation of ancient superstitions?

MCJ: I have no idea, but I would suspect the former. I would approach the story very warily. Vampire belief might be deeply rooted in the Balkans, but I doubt you'll find any "ancient superstition" even there that hasn't been thoroughly tainted by modern vampire lore. Fangs and blood-drinking are generally not present in the old stories. Victims were usually beaten up or suffocated.

Is it crazy that the town council issued a public health warning?

MCJ: Historically speaking, it's not that crazy. In past centuries, outbreaks of vampire hysteria, especially in Central and Eastern Europe, often coincided with outbreaks of tuberculosis and deadly plagues. Peasants had no other way of explaining why everyone was dropping dead but by blaming it on witches and vampires or other supernatural creatures. In 19th-century New England, tuberculosis wasted entire families, one after another. Superstitious people believed that the first to die was somehow feeding on his surviving family members. (Related: "'Vampire of Venice' Unmasked: Plague Victim & Witch?")

Why did people begin believing in vampires?

MB: Especially between the 16th and 18th centuries, little was known about what happens to the body after death. During plagues and epidemics, mass graves were continually reopened to bury new dead. People sometimes exhumed the bodies of the diseased to look for possible causes. Reports about vampires describe exhumations weeks or months after death, during the body's decay.

MCJ: Bodies weren't embalmed back then. They rot, to be quite frank, in grossly different ways. If a bunch of people in the village started dying in mysterious ways, they'd dig up the first one to die, see that his corpse didn't look quite right, assume that was blood flowing down those cheeks (it's called purge fluid in modern forensics, a natural byproduct of decomposition, but it's not blood), and generally burn the body. End of vampire.

Savanovic supposedly survived in spirit as a butterfly. Are there other twists on the classic vampire story?

MB: Sometimes it was thought that the body turned into a wolf or dog because near the grave of the vampire, there were footsteps of these animals. Actually, the earth had been disturbed by stray and hungry dogs attracted by the smell of the decomposing body.

Why is garlic anathema to vampires?

MCJ: People used to believe that strong-smelling stuff like garlic was apotropaic, meaning able to ward off evil spirits. But the specific garlic-vampire connection was popularized by 19th and 20th century novels and movies. A kind of [Romany] vampire, for example, is instead deterred by burning turmeric. Garlic won't bother them.

How do modern interpretations of vampires differ from older ones?

MB: Ancient reports speak about vampires as bloated corpses of ordinary people with blood around the mouth. In the movies, the dead are charming, seductive, often aristocratic, or with superhuman powers.

MCJ: The modern fascination with vampires is fueled by books and movies. Since the early 19th century, that has turned on illicit romance. Forbidden love. It was somehow thrilling to cross the line and love a vampire, or to be seduced by one. Hardly any of that is in the folklore, though. (See: "Vampire Expert Digs His Fangs Into 'True Blood,' 'Twilight.'")

Has there ever been any proof that a vampire existed?

MB: No. All the old reports about vampires talk about real events and real exhumation of bodies of suspected vampires. But they are misinterpretations of the transformative phenomena of corpses: Every exhumed vampire was actually a normal, decomposing body.

Why does this belief in vampires hang on?

MCJ: Fear of the dead. The same reason that people, deep down, are still afraid of ghosts. A vampire is a dead body brought back to life, so to speak, perhaps by the devil or an evil spirit.