To understand what an invasive species is, you must first understand the difference between an exotic species and a native species. An exotic species is any species, including its seeds, eggs, spores, or other biological material capable of propagating that species, that is not native to that habitat. Other terms sometimes used for exotic species include: non-native non-indigenous alien A native species is a species that, other than as a result of an introduction, historically occurs/occurred in that particular habitat. An invasive species is an exotic species whose introduction into an ecosystem in which the species is not native causes, or is likely to cause, environmental or economic harm or harm to human health. It is important to note that when we talk about a species being invasive, we are talking about ecosystem or environmental boundaries, not political ones. A noxious weed is an invasive plant that is legislated under the BC Weed Control Act.