The infamous drug lord Pablo Escobar was notorious for smuggling cocaine, but perhaps less known for illegally importing exotic species to his personal zoo. Soon after Escobar's demise, the animals were left alone, and now, one of these species has invaded the Colombian countryside ' a herd of more than 30 giant hippos! Join Nat Geo WILD for an exclusive look at the so-called "cocaine hippos" and the battle to control this thriving African invader.

Giant swamp rats are taking over the U.S. and destroying fragile ecosystems from Maryland to Oregon. The rodent, known as nutria, is native to Argentina, but was introduced to the U.S. during a "get-rich-quick" scheme to farm the animals for their fur. Now there are 20 million in Louisiana alone, and Nat Geo WILD is on the front lines with experts trying to curtail the invasive species.

Australia is being overrun by an invader. At as many as twenty-three million strong, feral pigs have already caused untold damage, and further destruction is inevitable if they're not stopped. Highly intelligent, hardy, and adaptable feral pigs are thriving in the land down-under. Here, they're endangering native species, spreading disease, destroying farmland, and even attacking people. Deliberately introduced by humans centuries ago, now its up to humans to keep their populations in check. Scientists and citizens are now resorting to a range of methods to defend their country.

Major cities in the United States are in the grip of an invisible invasion. More and more people are falling victim to one of mans oldest parasitic pests, one that lives in colonies hidden in our furniture and literally drinks our blood while we sleep: bed bugs. From apartments in New York to caves in Arizona, join researchers, entomologists and exterminators as they struggle to better understand bed bugs and find ways for us to survive the impending bed bug invasion.