Everyone believes that UFOs are aliens, but just to be clear UFO means Unidentified Flying Objects, and this has nothing to do with extraterrestrials from another planet.
It is true that UFOs may transport aliens, but so far, aliens have not been seen controlling UFOs, so there should not be any correlation.
I think UFOs are flying craft, but like many other craft, they simply maybe remote control craft. i.e. they do not have aliens within them.
Let me know your thoughts, and any experience you have come across.