Vampire bats don’t have the best reputation. For one thing, they are bats, and despite the value of bats and their great variety — about a quarter of all mammal species — not everyone loves them.

It might have to do with the viruses they host, which wouldn’t be much of a problem if we left them alone. Or it might just be that the fluttering of bat wings at night strikes some anxious chord in most humans. But these are not the bats thought to be the source of the new coronavirus.

And then there’s the vampire thing. But bats are not Dracula, or any of his animated fellow blood fiends in shows, such as Castlevania. Vampire bats are, in fact, the soul of cooperation, with a complex social structure. Like good toddlers, they have learned to share. For the bats their lives depend on it.

If a vampire bat drinks from a cow’s ankle one night, it is likely to share that meal with another bat. They do it via regurgitation, but that’s just a matter of style. Blood meals are hard to find, and they don’t keep you going for very long. By one estimate, a bat needs to feed every 48 hours to survive. That’s a good evolutionary incentive to develop food sharing.