WATCH: Why do Bats Transmit so many Diseases like Ebola?

Nipah, Hendra, Ebola, Marburg, and SARS are some of the world’s scariest viruses. They can be extremely fatal, like Ebola - which has the capacity to kill 90 percent of the people it infects - and can be extremely fast to spread, like SARS. What binds these terrible viruses together is not only the fact that they're all carried by bats, but also that each of them has surfaced in humans in just the past 50 years.

So what is it about the past 50 years that's suddenly brought all these viruses to the forefront? In the latest episode of MinuteEarth, Kate Yandell explains that because humans and our farm animals have been increasingly encroaching on the territories of wild bats, we’re now in more frequent contact with them than ever before. Plus bats are the perfect carriers of a virus - they love company, and will often roost with hundreds or thousands of their peers in close quarters, allowing the viruses to spread, sometimes even across species.

And on top of all of that, infected bats don’t die from the disease, which gives the viruses plenty of time to find a new host. What makes these little mammals more resistant to a virus that can topple an otherwise healthy human being? Flight. Flight might have helped bats gain virtual immunity to viruses, while training the viruses to be virtually immune to us, says Yandell. Watch the latest episode of MinuteEarth above to find out how.

Source: MinuteEarth