I believe, after many years of studying the subject of the UFO, that Earth has been and is being visited by other life forms. I suspect many of these machines stay here and where better to park than in the oceans. Many reports by retired military and commercial pilots report craft entering and leaving the waters of the ocean.
I also believe that there are many different groups that are doing the visiting and that some are more advanced than others. The motives I suspect too vary amongst the groups with the chief motive being exploration. Many of these vehicles could be unmanned as well. Not to different from what we do by sending probes out to explore.
Some contact reports indicate to me the beings were robots of some sort. The Pascagula case being one of them. Other reports clearly indicate living beings though some could be a type of android.
I wonder how much these various groups know about each other. If they are checking us out, then they are clearly aware of each other. Maybe some have intermingled like various races here. Maybe some of them could not begin to do so as biology would not allow. And still others may just pop in through a window they can open from another dimension.
I think cattle mutilations are done by one of these groups. This seems most likely to me. Even human mutilation cases have taken place.
Would some of these groups abduct humans for testing? Absolutely. Not much different than humans doing the same to animals with tag and study programs.
How fascinating it would be to be able to really learn about another culture from another world. Would they have music? What styles, instruments and time signatures? Perhaps they don't even hear as we do. What about sexual energy and animal lust? Alien Porno? God, food, sports, war and gambling? The list is endless.
One thing is certain. Some of them have made machines that failed to operate properly and crashed. The savages collected the remains for study. That seems like a major blunder. Oh well. Now we are in the age of the flying triangle which seems to say take a look at me! So many questions. So few answers.