Battle Butterflies
biologists, Department of Defense, engineers, giant squids, GPS, helicopter, humanity, Illustra Media, Intelligent Design, internal clock, Life Sciences, magnetic field, Metamorphosis, Metamorphosis: The Beauty and Design of Butterflies, Mexico, military, monarch butterfly, Philip Daniel, sharks, solar compass, submarine, whales
Every year, around a billion monarchs travel from across North America to gather overwinter in a few specific locations in Mexico. Source