Standing between two majestic peaks in the Pyrenees mountains on a blazing hot September afternoon, scientist Will Hawkes glanced down at his feet to witness a stunning sight. “There were so many small orange/yellow flies it was as if the ground had become a living carpet, humming with energy,” he recalled.
“To see so many insects all moving purposefully in the same direction at the same time is truly one of the great wonders of nature,” team leader Karl Wotton, a bioscientist at the University of Exeter, said in a statement. Starting in 2018, Wotton, Hawkes and their fellow researchers visited the site every fall for four years to monitor the number of day-flying insects migrating south through the pass and identify the various species. You can watch one of their videos of migrating hoverflies below.