The vampire bat’s diet consists of blood. It prefers to feed on domestic animals such as cows and pigs, but when it does so, there is a risk of transmitting pathogens such as rabies. Now, a new study lead by Assistant Professor Kristine Bohmann from the Natural History Museum of Denmark, University of Copenhagen, describes a new DNA method to screen vampire bat stomach and faecal samples to determine which animals the bats have fed on blood from. Furthermore, the authors show that the technique can be used to assess the vampire bat’s population structure.