WATCH: Mayflies swarm in North Carolina towns

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Mayflies have swarmed North Carolina towns along the South Fork River this summer.
 
Channel 9 news partner Gaston Gazette reported they have obscured streets lights and overrun pedestrian bridges.

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The flies hatch, swarm and dies – all within their 24-hour lifespans.
 
Two towns, Cramerton and McAdenville, have issues with the swarms of mayflies, the Gazette reports.
 
Derek Merrill, a firefighter with the Cramerton Fire Department, told the Gazette that he sees mayflies throughout June and July. They hatch when it gets hot or after a good rain.

Bad news for local residents: Eyewitness News reporter Ken Lemon found out the bugs are causing headaches even after they die and more invasions could be on the way.