Toronto is once again the backdrop to a giant sex party involving millions of tiny hovering bugs. Every Spring and Fall, sometimes up to four times a year, countless numbers of chironomids ("midges" to you and me) drift through the city in search of a mate, meaning that for the next few disgusting days every drink and open mouth in the city is at risk of invasion.

The densely packed clouds that often gather in shafts of sunlight or close to bright lights are actually sexually active females trying to entice obliging males to engage in coitus. The creatures normally like to hang around the waterfront, but onshore winds often drive them inland in massive swarms of up to 4,000 bugs per square metre.

Happily for Toronto's humans, the infestation is due to die down in the next week or so. Until then, the best way to steer the little creeps away is to set up a bright distraction lamp on your balcony, deck, or porch, says Ontario Science Centre expert David Sugarman.

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

Image: Andy's Camera /blogTO Flickr pool.