Non-native iguanas introduced to Florida dig burrows that damage cement foundations and sea walls. Some green iguanas, such as this one photographed at a front door in Lake Worth, Fla., have lost their fear of humans and are often drawn to houses where pet food is left outside or where landscaping includes ornamental flowers such as hibiscus. In a new study led by a University of Florida researcher, 137 non-native species are documented as entering Florida between 1863 and 2010. Floridaâs invasive amphibian and reptile numbers lead the world. Photo taken Dec. 3, 2006.