Well, this is not about the migration of people from rural to urban areas. Rather, this is the story of an epic migration in which every year, millions of dragonflies fly thousands of kilometres across the sea from southern India to Africa. So says a biologist in the Maldives, who claims to have discovered the longest migration of any insect. If confirmed, the mass exodus would be the first known insect migration across open ocean water. It would also dwarf the famous trip taken each year by Monarch butterflies, which fly just half the distance across the Americas.

Biologist Charles Anderson has published details of the mass migration in the Journal of Tropical Ecology. Each year, millions of dragonflies arrive on the Maldive Islands, an event which is well known to people living there.

“But no-one I have spoken to knew where they came from,” says Anderson, an independent biologist who usually works with organisations such as the Maldivian Marine Research Centre to survey marine life around the islands.