British Columbia

Flying ant invasion in Vancouver a brief glimpse into the sex lives of insects

Every summer, including right now in Vancouver, swarms of normally wingless ants take flight from their colonies for a brief orgy, more politely known as a 'nuptual flight.'

Every summer, swarms of winged ants emerge from their colonies for the brief orgy known as 'nuptual flight'

Flying ants on a vehicle Monday night in Vancouver. The winged ants are the reproductive males and females of a colony, which take flight to mate. (Cliff Shim/CBC)

It may be alarming to see thousands of winged insects emerge from the sidewalk, or worse, your basement.

But take comfort in the fact the flying ant invasion will be over soon — and it will end better for you than for the male ants.

Every summer, including right now in Vancouver, swarms of normally wingless ants take flight from their colonies for a brief orgy, more politely known as a "nuptual flight."

Clearly some people have been grossed out

Here's your guide to what's going on and when it will end

What you're witnessing is a "tiny slice" of the biology of an ant colony that's been growing somewhere underground for months, said Murray Isman, a professor of entomology at the University of British Columbia.

The winged ants are the reproductive males and females of the colony, which grow wings for their brief flight.

They mate, either on the wing or on the ground, then the successful females fly off as future queens of new colonies somewhere else.

For the males, their life is over.

"That's their sole function in life," said Isman. "A short but exciting lifetime, mating and hoping to fertilize a future queen that will survive long enough to start her own colony."

The successful females will fly off in the hope of starting their own colony. The males will die. (Cliff Shim/CBC)

Why they swarm by the thousands

Only a few get lucky, said Isman.

"This is the sort of event where 5,000 emerge and only five or ten out of those 5,000 are going to be successful at creating new colonies," he said.

"So a lot of them don't make it and that's part of the game."

Scientists believe there could be a benefit in swarming all at once, rather than daintily emerging two by two.

"If they come out in the thousands at one time … it sort of overwhelms the predators and  gives a few a chance to escape in the confusion."

A lone flying ant on a CBC News vehicle. Would it get lucky in its search for a mate? (Cliff Shim/CBC)

It will be over soon, but the ants won't be gone

The phenomenon is quite ephemeral, said Isman, over for any one colony in about 48 to 72 hours.

Though over a summer, people may witness several bouts of of flying ants, with different species having slightly different reproductive periods.

"It's pretty alarming for homeowners ... especially if [they're] coming out of your basement and trapped in the house," said Isman.

"All of a sudden your windows are completely covered with them, which happens from time to time, but again, it's a very short-lived phenomenon."

What that flight of fancy tells you is there is a colony of worker ants nearby, somewhere, growing for months.

"It really points to the fact that we live with insects intimately and around us most of the time and don't really pay any attention ... until they become a nuisance to us or alarm us."

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