Bats have lost some genes involved in that response, which makes sense because the inflammation itself can be very damaging to the body. They have a weakened response but it is still there. Thus, the researchers write, this weakened response may allow them to maintain a “balanced state of ‘effective response’ but not ‘over response’ against viruses.”

How to manage and contain the current outbreak of the virus officially known as 2019-nCoV, is, of course, of paramount importance now. But tracing its origin and taking action to combat further outbreaks may depend partly on knowledge and monitoring of bats. “The outbreak can be contained and controlled,” Dr. Daszak said. “But if we don’t know the origin in the long term then this virus can continue to spill over.”

Scientists in China were already studying the bats carefully, well aware that an outbreak like the current one would most likely happen.

Last spring, in an article on bat coronaviruses, or CoVs, a group of Chinese researchers wrote that “it is generally believed that batborne CoVs will re-emerge to cause the next disease outbreak.” They added, “In this regard, China is a likely hot spot.” This wasn’t clairvoyance, but conventional wisdom.

Certainly, rodents, primates and birds also carry diseases that can jump and have jumped to people; bats are far from alone in that regard. But there are reasons they have been implicated in several disease outbreaks and are likely to be implicated in more.

They are numerous and widespread. While bats account for a quarter of mammalian species, rodents are 50 percent, and then there’s the rest of us. Bats live on every continent except Antarctica, in proximity to humans and farms. The ability to fly makes them wide-ranging, which helps in spreading viruses, and their feces can spread disease.

People in many parts of the world eat bats, and sell them in live animal markets, which was the source of SARS, and possibly the latest coronavirus outbreak that began in Wuhan. They also often live in huge colonies in caves, where crowded conditions are ideal for passing viruses to one another.