Common European Yellowjacket Vespula vulgaris

This yellow-and-black predator has become a global invader found from the UK to Australia, Germany to China. But here's where it gets strange: the North American wasps long thought to be this species turned out to be something else entirely—a different species (Vespula alascensis) that scientists only identified in 2010. This aggressive wasp has become an ecological nightmare wherever humans have accidentally transported it, highlighting how difficult it can be to distinguish invasive species across continents.