Vampire bats have been put on a treadmill as a study showed the special way they use blood for energy – as well as how quickly they can run.
Footage shows one bat using its wings to sprint along inside a plastic box at up to 30 metres per minute.
The vampire bat is one of only a few species that can manoeuvre skilfully on land.
It uses this ability to quietly approach sleeping prey, such as cattle, pigs and chickens, before making an incision with its razor-sharp teeth.
Twenty-four vampire bats were captured from Belize and fed enriched cows’ blood for the Canadian study.
Researchers looked at the carbon dioxide they exhaled on the treadmill and found traces of amino acids, the building blocks of protein.
The ratio of CO2 to oxygen (respiratory exchange ratio) stayed the same at all speeds.
It suggests the bats’ main source of energy was their protein-rich blood meal, rather than the stored carbohydrate and fat primarily used by most other mammals.
Researchers say it shows “how strongly metabolism can be shaped by a specialized diet” because the diet of vampire bats is relatively low in carbohydrate and fat.
Common vampire bats are only about 7-9cm long but can double their weight after one blood-sucking feeding session.
They emerge at night, using sonar to navigate and detecting prey using heat sensors in their face. A strong anticoagulant in their saliva stops the blood of their prey from clotting during a meal.
The study, by Giulia Rossi at McMaster University and Kenneth Welch from University of Toronto, is published in the journal Biology Letters.