Invasive non-native species
The introduction of new species to the UK, either deliberately or accidentally, has occurred for thousands of years.
Many of the species have escaped from private collections and have spread rapidly at the expense of our native species, for example the grey squirrel. These are termed Invasive Non-Native Species, or INNS. Invasive non-native species have an impact on biodiversity by out competing native species because they dominate or destroy habitats, or by introducing new diseases or parasites. These can be plant, animal or insect species.