what do scientists think of alien abductions, what is the scientific reasoning or thinking?
There are a few theories, the most practical is a condition called "sleep paralysis," whose symptoms fit those of the descriptions of abductions. Other theories include sleep walking and hallucinogens
The reasoning at present is that virtually all reports of humans being abducted by alien life forms are outright fabrications - lies - or the result of hypnogogic and hypnopompic hallucinations. You can look up those two terms.
I'm not a scientist, but my best guess is they give the idea no credence whatsoever. No one claiming such an abduction has ever presented any physical evidence it occurred. Not a grain of dust or pollen, not a fiber, not a bacteria, nothing which does not have earthly origins has ever been recovered.
I believe those people believe they were abducted, but were not.
There are some psychological studies about them, but nothing really surprising. Most accounts are full of contradictions especially in repeated interviews, which suggests that they are fabrications. Not sure is yet, if they are intentional (attention seeking) or not intentional (for example a schizophrenia).
"Scientific thinking" and "Alien Abduction" really don't fit in the same sentence IMHO
There is no scientific thinking on the topic of alien abductions. It's not science and any credible scientist will laugh at the idea that aliens have visited Earth.