How does a vampire bat digest blood?

Answer 1

Although the average vampire bat weighs just about 40 grams, it usually drinks more than 20 grams of blood in a 20-minute feeding session. This adds another element of complexity for the bat, since this weight would make flying after a session of feeding quite impossible. But, the bat's digestive system has adapted itself to process its food rapidly and digest it.

The blood plasma, which has no nutritive value, is absorbed rapidly by the lining of the stomach, which is then swiftly taken to the kidneys by the circulatory system. From there it goes into the bladder and is excreted. In fact, the common vampire bat begins expelling extremely dilute urine, mainly comprising of blood plasma, within 2 minutes of starting to feed.

Then the vampire bat goes back to its roost, settling down for the remaining part of the night to digest its meal of blood. But, it now faces a new digestive problem. Since blood is basically protein, it creates a large amount of urea which has to be eliminated. Therefore, the vampire bat's urinary system utilizes a number of hormones which makes the urine very concentrated, containing less water and more urea.

Credit: http://www.buzzle.com/articles/vampire-bat.html

Answer 2

Vampire bats have specialized digestive enzymes in their stomach that help break down the components of blood, such as iron and protein. These enzymes allow the bat to efficiently extract nutrients from the blood meal, which is their primary food source. The digestive process also helps separate the liquid plasma from the solid components of the blood, enabling the bat to digest and absorb the nutrients quickly before excreting any waste.