It's long been known that vampire bats know where to bite in order to get a good meal of blood from a vein, but the researchers believe this is the first study to explain how they do it.
American and Venezuelan researchers investigated wild vampire bats in South America and discovered that nerve endings on their noses have a sensitive, heat-detecting molecule called TRPV1.
The study was published Aug. 3 in the journal Nature.
"Vampire bats feed on blood, and it's useful for them to have an infrared detector to be able to find the circulation," research leader David Julius of the University of California, San Francisco, said in a university news release.
Similar TRPV1 molecules in the pain-sensing nerve fibers in the human tongue, skin and eyes play a role in pain sensation. Various companies are trying to develop new pain drugs that target molecules such as TRPV1.
The Centre for the Conservation of Specialized Species has more about the vampire bat.