Bats are known to harbor highly pathogenic viruses like Ebola, Marburg, Hendra, Nipah, and SARS-CoV, and yet they do not show clinical signs of disease. In a paper published in the journal Cell Host & Microbe on February 22, scientists at the Wuhan Institute of Virology in China find that in bats, an antiviral immune pathway called the STING-interferon pathway is dampened, and bats can maintain just enough defense against illness without triggering a heightened immune reaction.