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The science of bloodsuckers

Bat Conservation Int'l via AFP - Getty
Vampire bats are the stars of Bill

Schutt's "Dark Banquet."

Between the "Twilight" movie and book series and HBO's "True Blood" TV series, vampires are getting a lot of exposure these days. But in biologist Bill Schutt's book, those fictional fang-wearers don't even deserve to be called vampires.

Instead, in "Dark Banquet," Schutt focuses on the true bloodsuckers of the natural world - vampire bats, leeches, bed bugs, the dreaded candiru fish and other critters that inspire tales as macabre and mysterious as any Halloween thriller.

"You couldn't make this stuff up," said Schutt, a professor at C.W. Post College of Long Island University and a research associate in mammalogy at the American Museum of Natural History.

Consider, for instance, the saga of Napoleonic soldiers who sipped from lake water infested with tiny larval leeches as they crossed from Egypt to Syria in 1799: "Unbeknownst to their hosts, the creatures quickly attached themselves and began to feed," Schutt writes. "Days later the men began to take ill and medical personnel were horrified to find their patients' noses, mouths and throats carpeted by blood-engorged leeches."

Schutt, whose specialty is the study of rare vampire bats, also takes you on a spooky tour of a guano-drenched icehouse in Trinidad, where he comes close to walking right into an elevator shaft filled with rainwater and bat droppings.

Elsewhere in the book, he explains why leeches were once inserted into women who wanted to pose as virgins on their wedding night. ("Arguably the strangest use of leeches on record," Schutt writes.) He does a reality check on the urban legends surrounding the candiru, or Amazonian "willy fish," which is said to swim right up a person's urethra. ("Apparently, it does happen, although thankfully, occurrences are extremely rare.")

And he tells a fascinating tale about the scariest bloodsucker of them all, a creature that lives among us and preys nightly on humans: the humble bed bug.

The bed bug bounces back

Bed bugs have made a comeback in urban environments, even in the tonier neighborhoods, and Schutt explains some of the reasons behind that. For one thing, residential pesticide spraying has given way to bait traps that are completely ineffective against blood-feeding bed bugs.

Univ. of Florida via AP file
A common bed bug is engorged

with blood after feeding on an arm.

Another reason is that the bugs have adapted to human behavior - just like pubic lice, their bloodsucking cousins. They've spread beyond the bedroom to new frontiers, thanks to a mobile society where the critters can hitchhike on cushions, suitcases and even clothes.

"When people come over to your house, where do you have them throw your coats?" Schutt asked. "Right: the bed."

As bed bugs develop resistance to the pesticides that are available for use, they become more and more invincible.

"Within the next two or three years, bed bugs are going to elbow termites and roaches out of the way to become the No. 1 pest in the United States," Schutt told me.

Slimy science

Other bloodsuckers can actually be good for you. Schutt traces the rise, fall and renewed rise of leeches as a medical tool. The slimers work better than anything else for drawing off blood from a surgical site, and that's why physicians have taken advantage of the leech's talents for centuries - whether or not the use was justified.

Viktor Korotayev / Reuters file
A woman undergoes leech

treatment at a Moscow laboratory.

Leech-assisted bloodletting probably contributed to the deaths of George Washington in 1799, British poet Lord Byron in 1824 and Soviet strongman Josef Stalin in 1953. But they also contributed to the healing of John Wayne Bobbitt's widely publicized penile amputation in 1993 ... and the mending of wounds suffered by Schutt's own father in a horrendous ski-boat accident in 1973.

"I only found out about that when I was doing the research," Schutt said.

As you'd expect for a biologist, Schutt packs lots of scientific lore into the book, even if it doesn't have to do directly with blood-feeders. Along the way, you'll suck up some fun facts about horse evolution, bee disappearances and the crazy ideas people had about human anatomy centuries ago.

Vampyres vs. vampires

Now, about those bats: Schutt points out that the legends surrounding human vampires (whom he calls "vampyres," to distinguish them from the real bloodsuckers) actually predate the discovery and study of vampire bats. The first stories about vampire-bat attacks came back to Europe from South and Central America in the 15th century, and those tales became increasingly linked to the pre-existing folklore of vampyrism.

Much has been made of the fact that the existence of true vampyres (to use Schutt's term) is mathematically impossible, because the gang-fangers would quickly turn everyone on earth into fellow vampyres. The way Schutt tells it, they're biologically impossible as well.

Jerry Ruotolo
Bill Schutt is the

author of "Dark


Blood contains no fat and is largely composed of water - and for that reason, vampire bats have to drink half their weight in blood every night. They have to start peeing massive amounts even while they're feeding. With those kinds of habits, even the suavest vampyre would be romantically challenged.

"If there were a Dracula, he'd be a really skinny guy, and he'd be eating a lot," Schutt said.

Schutt argues that vampire bats have gotten a bad rap: Yes, the best-known species has been known to lap up human blood, but that's just because we've invaded their space. And the other two species of vampire bats have become exceedingly rare, thanks to decades of indiscriminate eradication efforts.

"These bats are really not a problem, they rarely if ever have any encounters with humans, and they really don't do much damage with regard to economics," Schutt said. "If anyone took the time to figure it out, they could be considered threatened in some areas."

If allowed to live, they could be even be of service to humans. "They have anticoagulants in their saliva that are remarkable and much more effective than, say, heparin," Schutt said.

Looking beyond the medical benefits, Schutt argues that the world needs bloodsuckers - and not just for Halloween tales.

"If you think about blood as a resource, something that is nutritious and can be fed upon, then it makes sense that there would be these diverse creatures, as different as vampire bats and leeches, and that they've evolved similar characteristics to tap into this worldwide resource," he told me. "They've carved out their own blood-feeding niche, but they're also fed upon by other creatures. If they were suddenly to disappear, there'd be some real problems."

For more batty science, check out our roundup of the world's 10 scariest animals, some good news about Tanzania's "flying foxes," LiveScience's tale of a moldy bat mystery and's report on duet-singing vampire bats. Here's still more Halloween science to sink your teeth into: