S1, E4: 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.