Bats Glow Green Under UV light, But Why Remains a Mystery
Athens, GA – July 29, 2025 – In a surprising revelation, researchers have confirmed that several North American bat species exhibit photoluminescence – the ability to glow when exposed to ultraviolet (UV) light. A study published today in the journal Ecology adn evolution tested 60 museum specimens from six species and found all emitted a green glow in the 520 to 552 nanometer range.
The bats identified as exhibiting this phenomenon include the big brown bat (Eptesic brown), seminole bat (Lasiurus seminolus), eastern red bat (Lasiurus borealis), gray bat (Myotis grisescens), southeastern majority bats (Myotis austroriparius) and the Brazilian free-tailed bat (Tadarida brasiliensis). The glowing was observed in the wings and hind legs.
This isn’t the first time photoluminescence has been observed in mammals; flying squirrels and platypuses also display the trait. However, the function of this glow in bats remains unkown.
“This may not seem very vital,but we are trying to understand why these animals glow,” said Steven Castleberry,a wildlife biologist at the University of Georgia,in a statement to Smithsonian Magazine. “It’s cool, but we don’t know why it happens. what is its evolutionary or adaptive function? Does it actually benefit bats?”
Researchers hypothesize the glow could play a role in interspecies communication, mate attraction, or be a byproduct of natural pigments. A complicating factor is the possibility that the luminescence may be caused by chemical preservatives used in the museum specimens, rather than being a naturally occurring phenomenon.
“We are still in the early stages of understanding whether this green light truly belongs to nature,or is simply the result of chemical interactions,” the research team’s report states.
A 2023 study identified fluorescence in 125 species, where some birds, fish, and insects utilize the ability for attracting mates, camouflage, or predator warnings. Photoluminescence remains a rare trait in mammals.
The study authors emphasize the need for further examination into the role of photoluminescence in mammals and its evolutionary history. The discovery highlights the ongoing nature of scientific inquiry and the potential for uncovering new mysteries within the natural world.
