How can we difernciate native and non native English?

I assume for the same reason native English speakers mix English with whatever language they're learning. This is just something people do. Once you get good enough to do so, you begin speaking a...

they are both plants

one of the non native species is the Burmese pythons due to the fact that their owners release them into the everglades and they start to breed and fight over niches with other animals

Many animals affect native Australian animals. They include foxes, rabbits, rats and mice and of course humans. Foxes have the effect by killing meat eating animals food and killing native small game...

No. It is idiomatic slang.