Over the past two months, shepherds and ranchers in rural Mexico have become increasingly concerned that the Hispanic vampire beast el chupacabra might be stalking their livestock.

The chupacabra (the word means "goat sucker" in Spanish) is the world's third best-known monster after Bigfoot and the Loch Ness Monster, and first appeared in 1995 Puerto Rico. It had a heyday of about five years, when it was widely reported in Mexico, Chile, Nicaragua, Spain, Argentina, Brazil and Florida, among other places, though sightings have decreased since then.

According to some, the monster has returned.

Reporter Pedro Morales, in an article appearing at Argonmexico.com (translated by chupacabra researcher Scott Corrales) notes, "Shepherds... in Puebla State are frightened by the attacks on their flocks by either the chupacabras, wild dogs or some other wild creature that they've been unable to hunt down, and which has caused the deaths of over 300 goats for some 50 days now."

It's not clear from the news stories why, exactly, the presumably mythical chupacabras are suspected. Several shepherds reported seeing dogs fleeing from the livestock attacks. According to one rancher who claims to have had 62 of his goats killed, "They were killed at night, because I arrived in the morning and they were all scattered, with bite marks, and 10 goats had head injuries. It looks like dogs were involved, but not normal ones. Perhaps wild ones or something."

Many of the most sensational and "mysterious" aspects of the attacks are simply unproven or self-evidently false. For example, according to one news report, "over 36 animals had been beheaded in a strange way and without a single drop of blood in evidence."

Yet a close look at photographs of the carnage clearly shows that both claims are wrong. The animals were not "beheaded," but were instead attacked at the neck, a classic sign of a dog or coyote attack. Furthermore, the ground upon which the animals died is clearly soaked in a lot of blood — exactly the opposite of being "without a single drop of blood in evidence."

A search by local authorities searched in vain for the chupacabra, finding instead — you guessed it — some feral canines. The dogs were shot and killed, then eviscerated to see if their stomachs contained meat or blood from the slain livestock (which of course they didn't, since the dogs did not eat the goats nor drink their blood). All the evidence points to dog attacks, but of course journalists know that injecting the goat-sucking chupacabra into the story makes it much more interesting.

Benjamin Radford is managing editor of the Skeptical Inquirer science magazine. His new book is Scientific Paranormal Investigation; this and his other books and projects can be found on his website. His Bad Science column appears regularly on LiveScience.