Blacklegged Ticks Are on the Move (IMAGE) University of Pennsylvania Caption Blacklegged ticks have expanded to new areas of the Northeastern United States by migration, according to a study by University of Pennsylvania researchers. The findings have implications for strategies to control these vectors of Lyme disease. Credit USDA-ARS 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.