The definition of a native species is one that arrived without human intervention. You are correct that animals migraine all the time. Insects can travel accro

The definition of a native species is one that arrived without human intervention. You are correct that animals migraine all the time. Insects can travel accross oceans under certain favorable wind conditions. I live in an island nation, New Zealand, and insects from Australia show up every so often after getting blown here. They usually don't establish themselves as the conditions are not right for them to thrive.