“What claim do you have to this solar system?” the alien asked humanity. “You’re stuck on your own planet and we don’t want that world. We will begin mining operations on the rest of the system.”
That was the first and last message from the alien invaders. That message changed the world, of course. We tried every means we could to communicate with the aliens again. They had so much they could tell us about the universe.
It turned out the radio waves we used annoyed the living hell out of them.
And what do you do with annoying pests?