By Billie Rubin, Hemoglobin’s Catabolic Cousin, reporting from the labs of Stanford Blood Center
Vampire bats feed on the blood of other creatures, a hematophagy diet. There are three bat species whose only source of nutrition is blood: the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat.
These blood-sucking creatures, whose habits include sleeping suspended upside down in their caves during the day in complete darkness, live in colonies of about 100, sometimes up to 1,000 bats.
According to an article from National Geographic, “In one year, a 100-bat colony can drink the blood of 25 cows. During the darkest part of the night, common vampire bats emerge to hunt. Sleeping cattle and horses are their usual victims, but they have been known to feed on people as well. The bats drink their victim’s blood for about 30 minutes. They don’t remove enough blood to harm their host, but their bites can cause nasty infections and disease.”
So, if it takes 100 bats 15 days at 30 minutes/day (7.5 hours) to finish off a whole cow (~1,000 lbs), it would take them only about 4.5 minutes to draw one pint of human blood…