What is the only food of a vampire bat?

Answer 1

Vampire bats eat/drink blood from other animals. With their sharp fangs, they cut into an animal, and to prevent the cut from scabbing/cutting off the bllod flow, the vampire bat spits into the cut, which keeps the blood flowing and also prevents the animal from feeling anything. But sometimes the vampire bats get too greedy,thus causing them to drink too much blood, making them un able to fly until the blood digests.