I’m pretty sure that Agent Smith from The Matrix had it right when he described human beings as a virus. We pretty much do exactly what he describes: We find a home, replicate, consume all of the resources and then move on. It’s not exactly far from the truth, except in those instances where we stubbornly refuse to give up our homes and squalor in the wasteland that we’ve created.
The problem is that the wasteland is beginning to engulf the planet. The one thing Smith left out of his analogy is what we leave behind. And sometimes, the effects are just weird.