Vampire bats form close friendships with each other by sharing their blood in “a sort of French kiss”, a new study has found.
These bats, which are the only mammals known to feed on blood, share their meal by regurgitating it.
Scientists say the animals create long-lasting bonds through this life-saving act of cooperation.
They obtain their food by biting into larger animals including cattle and can starve if they have not eaten for three days.
Gerald Carter, the study’s lead author and a behavioural ecologist at Ohio State University, said: "We go from bats starting as strangers from different colonies to groupmates that act to save each other's life.”
"They have this 'boom and bust' foraging experience, so they either hit it big and get a large blood meal or they're starved for that night,” he added.
Prof Carter noted the study is the first to look at how strangers from the same species create and then maintain cooperative relationships.
The experiment took 30 bats from two different area of Panama and put them together in a laboratory in pairs and groups.
The researchers omitted to provide one of the animals with food and watched how it interacted with the others around it.
Over a duration of 15 months, many of the creatures groomed one another and then shared blood with those in need of food.
"We think of social grooming as a kind of a currency - a way to gain tolerance and bond with another individual,” Prof Carter said.
The research is published in the journal Current Biology.
The team is now looking into how bats choose their mates.
Additional reporting from PA
