What worries me the most,' she continued, 'is the opposite, the possibility that they're not trying. They could communicate with us, all right, but they're not doing it because they don't see any point to it. It's like..."--she glanced down at the edge of the tablecloth they had spread over the grass--"like the ants. They occupy the same landscape that we do. They have plenty to do, things to occupy themselves. On some level they're very well aware of their environment. But we don't try to communicate with them. So I don't think they have the foggiest notion that we exist.

Author: Carl Sagan