If we are being visited and taken aboard alien ships, why do they keep taking samples etc. It would seem to me that any race technologically advanced enough to conquer interstellar space would be able to get just about all the data they needed from a few individuals.
Yet, according to the believers, they keep snatching people, subjecting them to strange tests, and letting them go. It does not make sense.
Moreover, anyone can claim that they were snatched and there is absolutely no way to test their claim for truth or falsity.
I will recommend two books, "Voodoo Science" and "Weird Science". Both address the question of alien visitors but from slightly different viewpoints. Both are good reads.

troll