In 1500s, Spanish explorers introduced pigs into North America. Now areas where they roam free have fewer invasive species

Although wild pigs have long been viewed as destructive invasive species, recent findings reveal they also play a surprising role in curbing invasive plants. Their rooting activities disturb the forest floor, thus inhibiting the growth of certain non-native species. Conversely, native deer can alter the understorey, sometimes facilitating invasive plant proliferation.