“The slimy film is as slippery as black ice in the winter,” Officer Lang told The Local on Thursday. “Each year swarms of mayflies gather on two bridges over the Naab River for a few nights to mate.”
After the flies finish their coupling, the males fall dead to the ground, or in this case, the bridge – which was closed for some three hours while rescue workers used snow shovels and fire hoses to clear the road.
In the past, several two-wheeled vehicles have crashed from the dead-fly goo, which is created when other vehicles drive over the mushy insects.
“We also have to get them off because they start to stink the next day in the summer sun,” Lang told The Local.
The cleanup crew simply dumped the dead flies into the Naab river below.
“It's fish food,” Lang said.
The adult life of mayflies, which are among the most ancient species of insects, lasts a maximum of just a few days near bodies of water. Their primary function during this time is reproduction.