Maybe, but that's just an excuse to never do anything. And we can be fairly sure about some things. Rats in new Zealand, rabbits in Australia, cane toads in A

Maybe, but that's just an excuse to never do anything. And we can be fairly sure about some things. Rats in new Zealand, rabbits in Australia, cane toads in Australia, etc, etc. Further it takes time to remove these populations, so you can observe what happens when they're removed from a local area.