that's because most probably they are not predators or et's and more likely earthly phenomenonsThat would be why come and discover other inhabited planets like the earth, but doesn't make sense of the so called sightings that get reported. If they discovered earth but didn't want to make contact then it could be done from a distance that wouldn't involve the sightings being talked about. It would also, I would expect leave traces detectable by ourselves and despite searching for years there are no signs on other intelligent life so far detected.
i'm still of the opinion distances are too vast for intelligent life to reach us physically