Samantha Knight, University of Guelph (IMAGE) University of Guelph Caption As part of their multigenerational migration, monarchs from Canada overwinter in Mexico and green darners travel to the southern United States. Until recently, their small size has made individual insects hard to track. But it’s increasingly critical to do just that, said lead author Samantha Knight. Credit University of Guelph Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.