There seems to me to be a simple internal inconsistency in saying “I believe in UFOs” because if you expand that it reads “I believe in unidentified flying objects” because it is believing in something you don’t understand.
What they really mean is I believe aliens or spaceships are present in earths atmosphere/ near space but they would not say it because it quickly looks stupid.
I also believe there are things I can’t identify, sometime it lasts seconds before I identify it and in a few rare cases I still have not identified it – however until I identify it I can’t believe anything about it let alone pronounce facts about it.
The UFO fraternity relies on two other structures to keep there “dreams” alive 1. Conspiracy theories 2. You cant prove (or in this case disprove a negative). As usual for Woo Woo it usually fails basic tenants of critical thinking.
Just like others such as many alternative medicines, evidence of UFO beliefs must immediately be put to the side, pending further evidence because by nature they a prepositions that can not be tested using “Blind” or “Double Blind” research
By definition UFO claims require an observer primed to categorize it as effective/observed.
We can’t easily, if at all, test the Null case.