SLIDELL, La. -- It was like a scene out of a horror film.

A massive swarm of mayflies carpeted a north shore gas station Monday night.

"It was crazy," Slidell resident Kenny Hickman said. "You could hardly see the fuel pumps."

Hickman didn't get out of his truck to gas up at the Quick EZ station on North Military Road, but he did shoot cellphone video of the mayfly swarm.

"I said, ‘I'm not getting out,’ because they would get in my mouth, up my nose. There were so many of them," Hickman said. "I've never seen that much swarm."

Hundreds of mayflies still blanketed the outside of the gas station Tuesday morning.

Dead ones by the thousands littered the gas pumps.

The store's morning manager said the swarm of mayflies was so thick when she arrived for work that they completely covered the front door. She was afraid to walk in.

Audubon Butterfly Garden and Insectarium curator Zach Lemann said besides the mess, mayflies aren't dangerous or harmful.

"They don't bite," Lemann said. "They don't sting. They don't damage crops. They don't damage our homes."

The mayflies likely developed in nearby freshwater streams. Once adult mayflies emerge from the water, they do so en masse.

"They don't feed," Lemann said. "They live oftentimes for only one day, but that's enough time for them to mate and for the females lay their eggs in water, and then they die."

Mayflies are apparently attracted to light. That's why the swarm descended on the gas station after dark.

"The video clip that you all have shown has a lot of them aggregating around a light," Lemann said. "Typically, they would spread out a little more than that."

The mayflies provide a rare opportunity for locals. People have used real and plastic mayflies as bait to catch fish.

"I'd like to put a bunch on a fishing hook and fish with them," Hickman said. "You need to put four or five of them on the hook to catch them brim."

The mayflies will likely only be around in Slidell for the next two or three days.