"This colony included bats that were captured from completely different sites, meaning that many of them were strangers when we created the colony," lead author Imran Razik, a graduate student in evolution, ecology and organismal biology at Ohio State University, tells Treehugger. "Two of these strangers, Lilith and BD, gradually formed a strong grooming relationship in captivity, such that they were primary grooming partners. BD also donated food (ie. regurgitated blood) to Lilith more than any other bat." Vampire bats often groom each other and will regurgitate their meals in order to feed others that haven't been able to get their own meals of live animal blood. The researchers fast the bat colony in order to trigger food sharing between the bats.