The flu is common in humans, birds and pigs, and has even been documented in other animals like dogs, horses, seals and whales. And now scientists report first evidence of the flu in bats found in Guatemala.

The AP reports that a CDC outpost in Guatemala discovered what researchers are calling the "genetic material of a flu virus" found in the intestines of the Sturnira lilium, a little yellow-shouldered species of bat. They also believe that the virus has been growing for years:
Scientists suspect that some bats caught flu centuries ago and that the virus mutated within the bat population into this new variety. Scientists haven't even been able to grow the new virus in chicken eggs or in human cell culture, as they do with more conventional flu strains.

But it still could pose a threat to humans. For example, if it mingled with more common forms of influenza, it could swap genes and mutate into something more dangerous, a scenario at the heart of the global flu epidemic movie "Contagion."

These bats eat fruit and insects but don't bite people. Yet it's possible they could leave the virus on produce and a human could get infected by taking a bite.
The research has been posted online in the journal Proceedings of the National Academy of Sciences.