(WYFF) – Mayflies are hatching and invading northeastern Ohio. The swarm was so dense that it was captured on the weather radar of WOIO-TV on Wednesday. These mayflies come from the waters of Lake Erie. According to the Ohio Sea Grant research and education program, the mayflies begin as eggs burrowing in lake sediment, and after a year or two,

they swim to the surface, emerging fully winged. Adult mayflies vary in size from a quarter-inch to an inch long. They won’t be around for long, though. Individual mayflies live up to two days once they come on land. The swarms typically last about a month. Residents may find them annoying, but the mayfly swarm is an indication of good water health in the Great Lakes, according to Ohio Sea Grant. READ MORE