Howdy! It’s Joey, back with more Fun Fact Friyay. This fact is a bit of a mouthful, but also oddly wholesome?
Vampire bats feed blood to other vampire bats to build trust.
Think about the last time you went out to eat with someone. Did you share any food with your dining companion? Or maybe you were more like, “Sorry, Jenny, I ordered the milkshake hamburger and you opted for the half a breath mint special. You have no one but yourself to blame.”
Jenny can learn better next time. Alternatively, we can all take a page from vampire bats.
As the name suggests, these Dracula-esque creatures survive by drinking blood. That’s their entire diet. They can maybe go a night or two without a drink, but three days in a row with no blood would almost certainly result in the bat starving to death.
Similar to how birds regurgitate food for their babies, vampire bats do the same with their blood. However, they feed other adults, and they’re not related—they’re just good pals.
Ohio State University behavioral ecologist Gerald G. Carter was interested in exploring how the bats built these bonds with each other. Previous research suggested animals “raise the stakes” in relationships, starting with low-cost investments and then gradually transitioning into larger ones that might contain more risk.
To test this hypothesis, Carter found 30 vampire bats from two different Panamanian colonies and put them all in a lab. Unfamiliar bats teamed up and soon began grooming their partners, even though they were essentially strangers.
This grooming continued to increase until the partners moved on to a higher-risk moment of food sharing. The grooming leveled off after the pairs began sharing food, indicating that the bats had developed a higher level of trust.
Even after the bats were returned to the wilderness, the majority kept up the strong relationships they built in the lab. Some vampire bats maintain relationships for over a decade.
That’s longer than a lot of human friendships! Of course, if the cost of keeping a human acquaintance around means we have to mimic how vampire bats share blood, it might be worth going our separate ways.