Over 1,500 bat species carry thousands of deadly viruses but rarely get sick, and scientists are only just beginning to understand why

Bats possess a unique, preactivated innate immune defense that stops viruses from fully replicating, even after cell entry. This remarkable resilience stems from their ability to suppress excessive inflammation, a balance perfected over millions of years of evolution, particularly linked to the demands of flight. This evolutionary advantage allows them to tolerate deadly viruses without succumbing to them.