Why would you conceal yourself if you had made such a long journey to get here? I try to imagine the motivations of an alien race in visiting another planet or system, and the only two I can think of is acquisition of more resources or colonization (even if in the form of co-existence). And my instruments on the home planet would detect the technology which has the capability of transmitting electromagnetic energy which means radio and cell towers, broadcast antennas and lasers directed into space. All probes I would send would home in on those signals (not a bonfire in the backwoods). I would be interested in the city centers and the large concentrations of lifeforms, not the sparsely populated undeveloped areas. For all I know, those areas are not populated because of disease and/or contamination.
If we as humans found intelligent life on say...Europa or Titan, would we purposely conceal ourselves or would we send probes right to the source of any detected life? After assessing the threat of contact, we would attempt to communicate, not abduct one of them and take off back to earth. See where Im coming from?