PORTLAND, Maine — Black fly season is well underway, starting in most areas last month. It's peaking now, especially in central and northern Maine.
But there's reason to believe the weather this spring has contributed to a bigger swarm of them.
The sluggish start to spring, with ice on area rivers, a snowpack and cool air, resulted in a delay to the season.
There are over 40 species of black flies in Maine; however, only a few of them are known to bite and irritate people.
Black flies thrive in cloudy, more moist air, while on bright and sunny days they retreat.
Unlike mosquitoes, which can vary depending on the amount of rain and standing water, black flies breed in running water, like streams and rivers.
They also prefer clean water; in recent decades, cleaner waterways means more black flies.