Vampire bats made to run on treadmills in a lab reveal secrets of the special metabolism fueling them from blood consumed only minutes before. The research, published in the journal Biology ...

Researchers have targeted a substance in bat saliva called Desmodus rotundus salivary plasminogen activator (DSPA) to create the new drug. When a vampire bat bites its victim, it secretes DSPA.

Thus in both ecological and evolutionary terms, other members of this bat’s own species are its greatest competitors. So why would a vampire bat share its meal of blood? The answer is reciprocity.