“Mild winters and wet springs are more conducive to higher firefly populations in the summer,” University of Florida entomologist and firefly expert Marc A. Branham told CBC News in an email.
June in Windsor-Essex, for example, was one of the wettest on record for the region. More than 150 mm of rain fell in the region. Normal rainfall is 89 mm in June.
Environment Canada says June was the wettest on record since 2008.
“I love fireflies. They’re one of the classic things about summer and this summer everybody's coming out and saying, ‘where are all these fireflies coming from?’” said Paul Pratt, head naturalist at the Ojibway Nature Centre in Windsor, Ont.
It’s a question Pratt has been answering a lot this summer. Residents in the area have been reporting an unusually high number of fireflies at dusk.
Windsor resident David Panton is one who has noticed an increase.
“I’ve always loved fireflies. I love the way two of them will find themselves together in the air then flop, flop, flop in the grass.
What they do down there I don't know, but I have a hunch,” he said before laughing.
“It's been a wet summer but they also like tall grassy areas and with all the rain we've been having, vegetation is a lot higher thicker and more luxuriant this year. That's also contributing to great habitat for fireflies,” Pratt said.
Fireflies are more than just a pretty sight. They're an important part of keeping balance in the environment, Pratt said.
He said fireflies are actually little predators. They feed on and control populations of other insects and snails.
Pratt said the more fireflies, the better.
Kids enamoured by the bright little bugs had better catch them while they can because their lights go out by August.