[yokai]

The chance that there exist other creatures out there on different planets is high. Though I do not thing they are of a super advanced race, or just alike us humans. Frankly, a "alien" could just as well be a mindless dog like creature living on a planet for all we know. If they had been super-advanced, and capable of space travel then chances are also high that they would have arrived at Earth already and if they had done that then there would be no logical reason to keep said fact hidden, nor do I believe that an advance alien species would bother to keep it hidden just because someone asked "really nice".