Trajanus
Paranormal Adept
If beings from elsewhere are exploring other planets I think there is a good possibility that they, like us, would send robotic, unmanned probes. It would certainly make as much sense for them as it does for us. Its cheaper, its safer, and avoids the nasty prospect of unintended contact.
Judging by the number of large UFOs seen, capable of accomodating a crew, and # of humanoid cases, it seems that cost, and perhaps safety, is less of a limiting factor for them.