A monarch butterfly perches on milkweed at the Patuxent Wildlife Research Center in Laurel, Md., Friday, May 31, 2019. Farming and other human development have eradicated state-size swaths of its native milkweed habitat, cutting the butterfly's numbers by 90% over the last two decades. It is now under considered for listing under the Endangered Species Act. (AP Photo/Carolyn Kaster)