A vampire bat can bump up a splash of blood it has sucked in to help a hungry species friend. The generous behavior also occurs between individuals who are not related.

The bats were released

Researchers studied vampire bats in captivity for almost two years. When released, they then settled into a colony of wild bats in a hollow tree. The newcomers preferred to spend time with each other. The researchers compare their relationships with friendships between people that arise in high school and then last through life.

Vampire bats live long, up to 30 years. Start the clip and see how they feed each other with blood.

The new study is published in Current Biology.