I left an outside light on last night. Big mistake. This morning, hundreds, probably thousands of tiny deceased insects littered the ground, their tiny bodies spent after hours of copulating in the yellow glow of my porch light.

By the time the clean-up was complete, the little bodies filled a dustpan. Dozens more were scared up out of the dewy grass when I went to throw the dead ones out.

This is the second such uprising of sex-fuelled midges this year. In May, David Sugarman from the Ontario Science Centre explained how the clouds of insects appear during mating season. The bugs that gather in clouds, usually shafts of sunlight near bodies of water, are females awaiting the arrival of obliging males.

"When you see them, it's mating season," he said. "They don't bite people, they're just a nuisance."

"The reason we get huge clouds of these midges is that you can get, and this is an astounding number, four thousand larvae in a metre square, which means you could get thousands of adults emerging practically at the same time."

Sugarman said this year's swarm was likely triggered by a particularly wet Fall last year. Though they like to gather by water, bright lights and onshore winds easily move the mating clouds inland and into the mouths of walkers and cyclists.

Luckily, the swarms usually only last a few days, though each season could deliver up to four mass orgies. That leaves two more before the snow hits, maybe.

We asked if you had been affected by the latest influx of insects.

@blogTO Yes, for the last two days. Fortunately, they aren't able to get inside. Yet.

— George M ✈️ (@Overlaid) September 26, 2014

@blogTO Quite a few were swirling round our table at C'est What last night.

— Stephen Wickens (@StephenWickens1) September 26, 2014

@blogTO ya it's crazy ... This year so many Of those and wasps

— Ganzi Osteria (@GanziToronto) September 26, 2014

@ccath @blogTO They're simple bugs and think it's Spring right now.

— Adam (@manofthematch) September 26, 2014

@crobins72ca @blogTO They are everywhere!

— Theresa (@Teeda100) September 26, 2014

Chris Bateman is a staff writer at blogTO. Follow him on Twitter at @chrisbateman.

Image: Chris Bateman/blogTO