The only thing I can

     The only thing I can suggest is a trip to the psych ward.  No, I'm kidding.  Who knows what you're seeing, since the U in UFO simply means unidentified.

     Joking aside, Adobe After Effects has a tracking function for following a subject on screen.  Other NLEs probably have a similar function, but I have used it in After Effects.  Do a Google search on this, and you should be able to find instructions on how to do it.  One caveat, however:  Keep in mind that, depending on the method used for tracking, it can diminish the quality of your video.  You may have to experiment a little.