Millions of mayflies invade gas station in Wisconsin

NEKOOSA, Wis. (WSAW/Gray News) - The annual invasion of mayflies came once again this year, but this time there was a lot more of them at a BP gas station in a Wisconsin town, WSAW reported.

Millions piled on top of each other on the pumps and the store.

An employee said they were six inches high on the windows. They were attracted by the bright lights from the gas station at night.

Many people were afraid to use the gas pumps. An employee said that she saw at least six cars pull in the parking lot and then back out without pumping gas.

This strange phenomenon caused a lot of conversation on social media and many questioned why the bugs were back.

A professor at UW-Stevens Point said it was because there weren’t enough parasites to eat the mayflies this year when they emerged from the water.

“If our water quality goes down, like pollution for example, then we will start to see the populations decline simply because of negative changes in water quality. So mayflies also serve as a really good indicator of the health of some of our streams and rivers and some lakes,” said Jamee Hubbard, UW-Stevens Point biology professor.

The bug boom shows there is a healthy ecosystem in the Wisconsin River. Females can lay 400 to 3,000 eggs, according to Hubbard. Their life span is 24 to 48 hours. This is what causes a massive pile-up of dead mayflies in one location.

Hubbard assured that it is normal for them to make an appearance this time of year and the name comes from its origin story associated with a mayflower.