Surprise: Trillions of Insects Migrate

Some butterflies migrate thousands of miles a year, yet scientists have conjectured that most other insects spend their lives pretty much in one place. Not so. A 10-year study found that more than 3.3 trillion insects migrate high above southern Britain every year, especially in spring and fall. “People thought insects were passive and just got accidentally blown about,” says researcher Jason W. Chapman of the University of Exeter in England. “That is absolutely not the case. Insects make active choices about when to migrate and how to use the winds, often moving fast and over long distances, in beneficial directions.” What they are looking for, he surmises, is greener vegetation and better weather for breeding. Initial studies in Texas, India and China are showing similar patterns. Insect migration, Chapman says, “is starting to look universal.”