Watch vampire bats run on a treadmill..for science! Most mammals get the bulk of their energy for movement from fats and stored sugars. Amino acids, which make up proteins, typically supply less than 10 per cent of animals' energy. However, vampire bats subsist on a diet of blood drawn from their victims, which is rich in proteins but low in fats and sugars. To learn more about their metabolism, researchers at the University of Toronto Scarborough studied 24 adult vampire bats which were fed on