Invasive species threaten local ecosystems and the planet's biodiversity, but are they all as bad as we think they are? Plants, animals, insects and fish are moving in. In Nature Out of Balance: How Invasive Species Are Changing the Planet author Merrie-Ellen Wilcox profiles all-star invasive species around the world, starting in her own neighbourhood, and warns that humans are the most invasive species of all. We find out...