'Bugnado,' a massive tornado-like swath of swarming bugs, captured on video in Iowa

They look like tornadoes, but they're not. They're " bugnadoes," massive swaths of swarming bugs that swoop across the sky like a scene from an old sci-fi movie.

While many people were enjoying fireworks in the night sky on July 4, storm chaser and photographer Mike Hollingshead was getting images of an enormous bugnado in southwestern Iowa. He told Life's Little Mysteries that the swarm of bugs above the cornfields was so thick with bugs "it looked like it was smoking."

He managed to capture some of the scene with his video camera. A video of the event has gone viral with more than 65,000 views on YouTube as of Friday.

The bugs swirl in a ragged linear formation above a rural road as Hollingshead videotapes the scene. You can barely hear their sounds, which resemble a gust of wind.

The bugnado consists of swarms of either mayflies or midges, Joe Kieper, an entomologist and executive director of the Virginia Museum of Natural History, told Life's Little Mysteries . He said the two types of insects spend their early life stages as aquatic nymphs. They then come to the surface of the water, grow wings and fly away as adults.

The only thing left for them to do in the short time they have left is reproduce, which is where the bugnado come in.

"This is a mating flight," Kieper said, adding that the bugnado captured by Hollingshead is not that unusual, other than it is larger than most.

"The males are trying to impress the females, and the females select a mate."

What criteria they are looking for is anyone's guess, he said. Once they mate the males die and the females return to water where they lay their eggs then die, too.

"It's a remarkable video as it shows their cooperative behavior," he said.

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