An invasive species is any organism that causes damage to an ecosystem in which it did not originate. An invasive species may cause reduced biodiversity and extinction of other plants and animals in a new environment incapable of defending against its effects.
An invasive species may be disruptive to a new ecosystem by preying upon the native organisms, rapidly depleting natural resources and causing diseases that the ecosystem has no defense against. It may have detrimental effects on the environment, resulting in the destruction of native species' habitats. An invasive species may reproduce at a rapid rate, causing competition for food and other necessities that may result in the starvation or extinction of organisms that flourished prior to its arrival.