Scientists have figured out why vampire bats are the only mammals that can survive on a diet of just blood.
According to Huffington Post, they compared the genome of common vampire bats to 26 other bat species identified 13 genes that are missing or no longer work in vampire bats. Over the years, those gene tweaks helped them adapt to a blood diet rich in iron and protein but with minimal fats or carbohydrates, the researchers reported.
The bats are practically living Draculas. They bite and lap up blood from livestock or other animals at night. Most mammals couldn't survive on a low-calorie liquid diet of blood. Only 3 vampire species of bats can survive on blood alone, others need insects, fruit, nectar, pollen or meat, such as small frogs or fish.
"Blood is a terrible food source. It is totally bizarre and amazing that vampire bats can survive on blood, they are really weird, even among bats." said Hannah Kim Frank, a bat researcher at Tulane University, who was not involved in the study.
It is expected for creatures like mosquitos, bedbugs, leeches, fleas, etc.
With such a low-calorie diet, vampire bats can’t go long without a meal. In a pinch, well-fed ones will regurgitate their food to share with a starving neighbor. They seem to keep track of who has helped them in the past, said Hiller, noting that vampire bats have complex social relationships.