The Real-Life Vampire Animals Stalking Planet Earth

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A taxidermy specimen of a common vampire bat (Desmodus rotundus) feeding on a pig, at the Natural History Museum in Vienna. Sandstein / Wikimedia Commons CC 3.0

The first video of an alleged "vampire" squirrel surfaced recently. It shows the bushy-tailed mammal walking through forests in Borneo. That got us thinking: What other vampiric animals are out there?

Vampire Bats

Blood-drinking bats are probably the most famous of all the Earth's vampiric beasts. Vampire bats are nocturnal animals that live in central and south America. There are three different species: Two of them are rare and mostly feed on birds. The main one, the common vampire bat (Desmodus rotundus), feeds on large animals, such as cattle, deer and horses—and has been known to suck the blood of humans, but usually only when people sleep outside without protective netting. Although they fly to get around, they approach their prey on all fours, using the terrifying gait seen below.

At this point, they use specialized receptors on their noses to find warm areas to sink their teeth into. These receptors can recognize heat, or infrared radiation, from a distance of eight centimeters.

After creating holes with their tiny, razor-sharp teeth, they lap up the blood, using anticoagulants in their saliva to help it flow.

There are a few cases of vampire bats spreading rabies through their bites. But there's also evidence that bites from bats could help develop immunity to the virus, and large-scale killing of the vampires doesn't reduce rabies incidence.

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Little is known about the tufted ground squirrel, which may be able to kill animals much larger than it. It also feeds on seeds. J. Brodie and D. Augeri / Taprobanica

Vampire Squirrels

The tufted ground squirrel, or Rheithrosciurus macrotis, has the largest tail-to-body ratio (at 1.3 to 1) of any mammal. Another way to say that: It has the world's bushiest tail, taking up even more volume than the rest of its body.

And then there's the vampire thing. According to a 2014 study in the journal Taprobanica, Bornean locals told scientists that "the squirrel waits on a low branch for a deer to pass below, jumps on its back and bites the jugular vein, whereon the deer bleeds to death. Once dead the squirrel proceeds to disembowel the deer and eat the stomach contents, heart and liver. Dayak [Bornean] hunters sometimes find these disemboweled deer in the forest, none of the flesh eaten, which to them is a clear sign of a squirrel kill.… In villages close to the forest edge there were also accounts of the squirrel killing domestic chickens and eating the heart and liver only."

This may sound hard to believe, but local lore has in the past produced hard-to-believe anecdotes that have proved to be true. For example, Borneans also spoke of local deer-like creature that could hold their breath underwater for long periods of time. It turned out to be a real thing: Deer in the genus Tragulus do just that.

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A biologist puts her hand in a box with male genetically modified Aedes aegypti mosquitoes at an educational exhibition by British biotechnology company Oxitec in Piracicaba on March 5, 2015. Paulo Whitaker / REUTERS

Mosquitoes

These are pretty obvious, aren't they? But don't confuse their ubiquity with banality. Mosquitoes spread diseases such as malaria, dengue and yellow fever that collectively kill several million people every year. It's much more harm than vampire bats will ever be capable of.

Female mosquitoes are the only ones that bite—they need blood meals to provide sustenance for their offspring, and they need the protein in blood to produce eggs. Males typically feed on plant materials like nectar.

Sand Flies

Along the same lines, the females of many species of sand flies take blood meals to produce eggs. Sand flies, in the sub-family Phlebotominae, are fearsome because they spread several diseases, such as leishmaniasis, pappataci fever and Bartonellosis.

Leishmaniasis is caused by several types of protozoan parasites that infect 12 million people worldwide. The disease takes several forms; cutaneous leishmaniasis affects the skin and can cause nasty, sometimes disabling lesions, while the visceral form attacks the immune system and can be fatal.

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This species (Adetomyrma venatrix) is one of several known as "dracula ants," for their habit of drinking their larvae's hemolyph, equivalent to blood. Ant web / Wikimedia Commons CC 3.0

Dracula Ants

These guys don't have the word "vampire" in their name, but they've got something even better: the honorific of the Count Dracula, the anti-hero of the eponymous Gothic horror novel written by Bram Stoker.

And, they feast on hemolymph—the insect-version of blood—from their own young.

Most ants transfer food by regurgitating it into the mouths of their nest-mates. But not the dozens of species of so-called dracula ants, in the sub-family Amblyoponinae. These have the unusual habit of feeding on the hemolymph (the circulating fluid analogous to mammalian blood) of their own young. As the San Francisco Chronicle puts it, "the workers must prey on the larvae in their own nursery, scratching the skin of the larvae until they bleed, then chewing on the young, gorging on the blood and regurgitating the blood to feed the sedentary, wingless queens."

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A sea lamprey sucks the window of a fridge in Lisbon's restaurant Lisbon. They're slimy, pre-historic and considered a pest in North America. Jose Manuel Ribeiro / REUTERS

Lampreys and Leeches

Lampreys and leeches both suck the blood of other animals, especially fish. Several species of leeches, however, routinely latch onto humans when they get the chance. (These are a minority of leeches, though, considering there are more than 680 species of the creatures.)

The European leech (Hirudo medicinalis) for centuries has been used medically for bloodletting purposes. The ancient Greeks and other civilizations believed that ill health arose in part from an imbalance of the four humours—blood, phlegm, yellow and black bile—and removing blood via leeches could help restore that balance.

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A drawing of a candiru, also known as a vampire fish. Public Domain

The Candiru

The candiru or vampire fish (Vandellia cirrhosa) makes a living by feeding off the nitrogenous waste and urea excreted in fish gills. However, they have also been known to be attracted to another source of urea: human urine. In several rare instances, the fish have been documented to enter into the urethra of humans who decided it was a good idea to urinate while swimming in the Amazon river. Once in the urethra, the fish attempted to feed on the tissue therein. Pro tip: Don't pee when you're swimming in the Amazon!