1. who says it has to be intelligent
2. If you are the smartest kid at school, you made it to harvard, you got your MD, PHD and Nobel prize.......would you want to talk to the newborns in the jungles of Papua New Guinea?
That analogy is a lot like intelligent life, why would a race that is a few thousand if not millions of years ahead of us, who by now have evolved way past us, are far more advanced and could probably wipe the earth out, want to talk to us? why would they communicate?
If an intelligent species can travel through space quickly enough so that age does not impede travel, we must seem like monkeys with stone tools to them. Maybe they are watching but we dont see them =D