Light shines beneath a winged adult cicada and its discarded shell. Photograph by Roger P. Hangarter

The bugs pour out of the ground like a bubbling spring alive with energy, millions and millions of them clawing up through the dirt in the darkness of night. Sound like a science fiction movie?

Actually the amazing film Return of the 17-Year Cicadas shows the life cycle of cool insects that spend most of their lives underground, emerging every 17 years to mate and create a new generation over a few weeks.

Young cicadas crawl on a man's fingertips. Photograph by Keith Clay

The film won first prize in a competition sponsored by the National Science Foundation and Science magazine.

There are 12 groups of these 17-year cicadas (including the species Magicicada Septendecim, M. cassini, and M. septendecula), and in 2004 it was time for group number ten (Brood X—"X" is "ten" in Roman numerals) to come out into the world.

Trillions of them, living all those years in the soil and feeding on sap from tree roots, dug tunnels and came up through the earth, covering everything from trees to sidewalks. The largest numbers appeared in southern Indiana, southern Ohio, Washington, D.C., and Pennsylvania.

Two men decided to make a movie to share this extraordinary biological happening with people across the world. "Every day there was something new," said Roger Hangarter, one of the film's producers and a plant biologist at Indiana University in Bloomington.

Hangarter and university student Samuel Orr filmed the movie mostly in Hangarter's backyard.

"They came out of the ground every night for two weeks. My wife thought the yard was going to cave in!" Hangarter said.

Using time-lapse photography to take a picture every few seconds, the producers were able to show in a few minutes what took them hours to observe: The cicadas came out of the ground in their young form, known as the nymph form, and transformed by sunrise into winged adults.

In the summer of 2004, people living with the cicada invasion were fascinated by the short-term visitors. They talked about them, listened to the roar of their songs, and even ate them.

Hangarter spent many weeks observing and filming his subjects with Orr, but he was never tempted to munch on members of his project: "I heard there were even cookies made with cicadas," he said. "But no, I never tried one!"

If he changes his mind about tasting this group, he'll just have to wait another 17 years.

See the video Return of the 17-Year Cicadas. It may take several minutes to load.

Fast Facts

• Periodical cicadas get their names because they come out of the ground periodically, some on a two-year schedule and others after longer periods of time.

• Scientists think the cicadas seem to all come out at the same time because they wait for the soil and air to warm to 64°F (18°C) as summer comes.

• These bugs are big: Most measure 1 to 2 inches (25 to 50 millimeters).

• About one and a half hours pass from the time the cicada's hard shell cracks open to when its wings emerge.

• No one knows why the cicada's life cycle is 17 years, but some people suggest that because many cicadas emerge only after a long while instead of only a few each year, predators can't gobble them all up and kill off the species.