Large Mayfly Hatch Possible Cause Of Pierce Co. Car Crash La Crosse, Wis. was covered Sunday night when millions of mayflies from the Mississippi River hatched. The bugs made their way to buildings, lights and everything in sight. The cloud of bugs was so massive it got picked up on radar!
Cars, Sidewalks Covered In Mayfly Bugs In HastingsMillions of dead mayflies created an incredible mess on several streets in Hastings Monday morning.