The species, Glossophaga soricina, has the fastest metabolism ever recorded in a mammal, much like the nectar-eating hummingbird.
Cally Harper, a doctoral student at Brown University, along with a team of researchers, studied the hairs, called papillae. The projections are similar to human taste buds, though the bats' tongue hairs contain no sensory tissue.
Dissections revealed there were sinuses along the tongues that connected to the papillae, suggesting blood flowed through from the spaces to the the hairlike appendages.
Researchers set up high-speed cameras around feeding stations and waited for the bats. At 500 frames per second, videos showed that as the bats extended their tongues the papillae laid flat. Then, as the bats reached their tongues as far as they could, the hairs became erect.
The change in position came as the tongue tip flushed bright red. "The hairs separate from each other, and that creates a little space between each of the rows of hairs on the tongue," Harper said. "Each one of those spaces becomes filled with nectar."
"They could be really useful [inspiration] in bending around the curves of blood vessels and intestines," Harper added, "but also, they may minimize damage to some of those soft tissue structures."
Their study was published this week in the journal Proceedings of the National Academy of Sciences according to LiveScience.