Watch Clip

Why Bats Share Blood
1m 54s
Vampire bats will sometimes share a blood meal—but only with friends and family.
NOVA brings you stories from the frontlines of science and engineering, answering the big questions of today and tomorrow, from how our ancestors lived, to whether parallel universes exist, to how technology will transform our lives. Visit the official website to watch full-length documentaries, or explore our world through short-form video, on our digital publication NOVA Next.
Video description: For decades, rumors of alien spacecraft at Area 51 have captivated the public imagination. In what is now known as one of the most infamous government cover-ups, an absence of information fueled wild speculation. Discover how UFO stories may have served as a convenient smokescreen for secret testing of advanced military technology.
Vampire bats will sometimes share a blood meal—but only with friends and family.
You can make your vote incredibly secure on Election Day—all thanks to quantum mechanics.
A high school experienced several suicides so meditation was used to lower student stress.
When you send a text, how does your message make the journey to your friend’s phone?
A unique method to fight erosion saved the Montauk Point Lighthouse from disaster.
Certain gene forms increase your risk of developing Alzheimer's.
The proteins that make fish fluoresce could help scientists map the human brain.
A scientist dives beneath the surface of the frigid Antarctic ice sheet—and finds a landscape full of colors, light, and life.
Minerals are essential in making everything from skyscrapers tall, to mobile phones small.
Einstein's theory showed that time itself is affected by gravity.
Dive down to rare stromatolites—key clues to the evolution of virtually all complex life.
What does this geological wonder reveal about North America’s deep history?
Sea levels will rise by the same amount all over the world, right? Wrong. Here’s why.
Cyber threats from nation states and lone hackers are a persistent threat to America’s critical infrastructure.
We asked scientists, “What are your favorite images from space?” Here’s what they said.
The universe’s smallest particles fly down from space and emit from a radioactive rod.