First there was the dreaded seasonal flu, then birds started giving us the flu, and then some spring break revelers brought us pig flu. Now, the latest animal-related flu strain us coming from bats. A new strain of flu discovered in bats in Guatemala could someday pose a threat to humans. Other than an unverified report from Russia, this is the first solid evidence that bats harbor the flu virus. Scientists researching rabies in bats identified genetic fragments of the flu in the intestines of tiny yellow-shouldered bats. So far, they haven’t been able to grow the virus in a lab. Other viruses, such as hepatitis C, however, have been equally resistant to lab-growing techniques. At this point, the potential risk to humans is unclear. “This is the first time an influenza virus has been identified in bats, but in its current form the virus is not a human health issue,” the study’s lead author, Dr. Suxiang Tong, said in a CDC news release. If the virus were to mix with more common types of flu, though, it could swap genetic material and mutate into a more dangerous strain. While the yellow-shouldered bats don’t bite humans, they could transfer a mutated form of the virus to fruit that humans eat, leading to an infection. The CDC works with disease experts across the globe to monitor flu strains in animals that could pose a threat to humans. Fortunately, the bat virus in its current form “would need to undergo significant changes to become capable of infecting and spreading easily among humans,” said the CDC’s Dr. Ruben Donis.