As we recently reported, an alarming new report on the “kissing bug” has raised a huge amount of concern with the medical community by claiming that we are vastly underestimating how deadly it can be. But it’s the shocking truth about how this bug survives and where you can find it that you may find a good bit more alarming.

The study, published in PLOS Neglected Tropical Diseases, indicates that being infected by a parasite spread by this bug makes you two to three times more likely to die than had been previously thought. And it can spread this parasite to you by how it feeds – and the way it feeds is pretty gross, and also how it got its name.

The kissing bug bites humans on the face, often around the lips, while they are sleeping, and then the bug actually defecates into the open wound. A parasite named Trypanasoma cruzi often lives in these feces, and wreaks havoc on your body when dumped into the open wound, causing Chagas disease (trypanosomiasis).

You can see why they are also called “vampire bugs.” These insects feed on vertebrate blood, so not just humans are its victims. They are found mainly in the Americas, from the southern United States to as far south as Argentina.

It was Charles Darwin who made one of the first reports on their existence in a 1839 journal.

“At night I experienced an attack (for it deserves no less a name) of the Benchuca (a species of Reduvius) the great black bug of the Pampas,” Darwin wrote. “It is most disgusting to feel soft wingless insects, about an inch long, crawling over one’s body. Before sucking they are quite thin, but afterwards they become round and bloated with blood, and in this state are easily crushed. They are also found in the northern parts of Chile and in Peru.

“One which I caught at Iquique, was very empty,” the entry continues. “When placed on the table, and though surrounded by people, if a finger was presented, the bold insect would immediately draw its sucker, make a charge, and if allowed, draw blood. No pain was caused by the wound. It was curious to watch its body during the act of sucking, as it changed in less than ten minutes, from being as flat as a wafer to a globular form. This one feast, for which the benchuca was indebted to one of the officers, kept it fat during four whole months; but, after the first fortnight, the insect was quite ready to have another suck.”