Image via AP.

Four days to the inauguration and vampire bats are making a huge, unprecedented shift in their diet to feast on the blood of humans. A little on the nose, don’t you think?

According to New Scientist, this change is cause for concern for researchers in the Catimbau National Park in northeast Brazil, mostly because they reflect increased deforestation and hunting in the bats’ environment. When scientist Enrico Bernard and his team from Federal University of Pernambuco analyzed 70 pieces of D. ecaudata bat poop, 15 contained recognizable DNA, and three showed traces of human blood. “We were quite surprised,” said Bernard. “This species isn’t adapted to feed on the blood of mammals.”

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This species of vampire bat has evolved over eons to drink the blood of birds, and it may not sound like a big deal to sample here and there from other sources—i.e., your lovely neck—but mammal blood and bird blood have very different compositions of protein and fat. In previous experiments, scientists found that these bats would prefer to fast when offered blood from pigs or goats, some even unto death.

Bernard blames the switch on human encroachment, as the bats’ usual meal of guans and tinamous are disappearing, while several human families have moved into the park. The bats may reach humans through windows or, if they’re sleeping outside, in hammocks. I am personally very fond of bats and would not mind donating blood if I slept through the experience, but they are a big carrier of rabies and can also carry the hantavirus: much like making out with Dracula, there are consequences. Bernard says his team is following up with local residents to figure out how this blood drinking is happening so they can begin to assess the public health risk.

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“They are adapting to their environment and exploiting the new resources,” Bernard said of the ambitious creatures. We know exactly what he means by “new resources.”