Eli5: how do invasive species work?

Question

When you see lion fish or anacondas as invasive.. how does that work? If they live there how did they get there and what does it do to have invasive species that people are just killing animals to prevent it?

In: Planetary Science

Answer 1

There is a two-pronged test to determine if something is an invasive species:

1. Is it non-native to the ecosystem; and,
2. Does it cause or is it likely to cause economic or environmental harm or harm to human health?

The vast majority of introduced species are not invasive, but the few that are can cause a massive amount of damage.

In virtually every case, invasive species are introduced by humans, either intentionally or accidentally.