By CBC News, July 18, 2017
Leaving the nest or the birds and the bees: What causes bugs to swarm?
It’s not every day that you come across a swarm of hundreds or thousands of bugs, but you might be surprised to know what causes them.
On the weekend, a Saskatchewan woman shot a video showing swarms of insects near Old Wives Lake. It looks like mini tornadoes, but is actually swarms of mayflies.
Sean Prager, who is an entomology expert and assistant professor at the University of Saskatchewan, said there are a variety of reasons why so many mayflies might be around, including the weather conditions this year, or in the past few years when the bugs’ eggs were laid.