Today there is no place on Earth that does not harbour invasive exotic species. Invasive plants and animals can be found on every continent, including Antarctica, and within all waterbodies, including all oceans. In our increasingly connected world, with speedy commercial and recreational travel and the global movement of biological matter for food, invasive species are showing up at such a fast rate that there is no way to accurately count how many currently exist or how many are likely to emerge in the coming decades. Monitoring these species and controlling their spread is essential, as we increasingly understand the negative impacts they pose: their threat to our health; the toll they take on our commercial production; and the threat they pose to native ecosystems.

This Very Short Introduction provides a clear definition of an invasive species, and considers the myriad ways they are moved around the globe, and the ecological, social, and economic impacts they often impose.