The documentary focuses on the invasive species and pests that threaten forests, including the Asian long-horned beetle and the emerald ash borer, which have wiped out billions of trees in the USA. Across the border into Canada, the mountain pine beetle has halved the number of lodgepole pines, and the kissing bug, a carrier for Chagas disease, ticks and the Burmese python are also damaging woodland.
Examining the invasive species and pests that threaten cities, including bed bugs, termites, cockroaches, rats, mosquitos and coyotes. Cockroaches produce high amounts of allergens and are one of the causes of asthma for children in conurbations. In the USA, coyotes have begun to feed on pets and livestock and can now reach weights of 75 pounds, while in the southern states; mosquitoes have started to spread the West Nile virus.