Bats used to bear the unfair image that they were all blood suckers. Many now appreciate that bats are invaluable in controlling the insect population, and in pollination and seed dispersal. Keep those in mind as we tell you what else bats are good at: as reservoirs for deadly viruses. That's right - everything from SARS to the Ebola virus, as well as the new MERS virus, which is extremely deadly.

Now scientists are discovering that just under half of all fruit bats in a dozen African countries also harbor the Henipaviruses, which can be deadly to other animals and humans. A third of the bats also carry a rabies-like virus called The Lagos bat virus.

Researchers had tested more than 2,000 of the straw-colored fruit bat, which is the most widely distributed bat in Africa. The concern is that Henipaviruses can be passed in bat urine and other bodily fluids, putting people living near bat populations at risk. Outbreaks have killed horses and humans in Australia as well as pigs and pig farmers in Malaysia.

Bats have maintained viruses since ancient times. They are natural incubators since they can migrate long distances, live longer than 25 years, and hibernate, which keeps viruses alive. Bats are constantly shedding viruses through urine and droppings that easily infect other bats as they roost together in tight communities.

But they are also essential to our ecosystem, so we can't consider eliminating them. Scientists are focused on developing vaccines and antivirals to protect people. Their work will become increasingly important as humans continue to invade pristine ecosystems.