PORT CLINTON, Ohio — It happens every year along the Lake Erie shoreline, but you never really get used to it. Swarms of mayflies are being blown ashore, creating problems for cities like Port Clinton. 

Buildings in Port Clinton were covered in mayflies this week. While they make a complete mess, they're harmless. 

The bugs get blown to the Lake Erie shore when there is a northerly wind off the lake. The phenomenon happens for four to five weeks during May and June, and since they're attracted to light, many cities along the shoreline will turn out the street lights to help keep them at bay. 

Additionally, mayflies are a sign of a healthy lake. But since they can cause a slippery mess, businesses often hire people to clean them up.

Charlie Burns is a retired school superintendent who now works as a pool and ground supervisor for Our Guest Inn & Suites. He said he hasn't seen this many mayflies in seven years. 

"We try to get the walkways cleared right away so people can leave their rooms and leave the hotel," Burns said. "We try to blow their cars off so they don't get mayflies inside. It's just a never-ending battle this time of the year."

Street sweepers also take part in the cleanup, as squished bugs can make roads slippery.

The bugs have no mouths so they don't bite, and they will die off within 24 hours, just in time for another round to get blown ashore.