Many introduced plants have become naturalized across the continent and some are replacing North American native plant species.
许多引进的物种在整个大陆都已经顺化，一些种类正在取代北美本土植物种类。
2
They feed on plants and small animals and, in captivity, on small crustaceans and other foods. They have become naturalized in many parts of the eastern U. S.