my personal belief is UFO's are demonic and possibly technology used to bring those in power to believe that they are some sort of other life form, when in reality its just another satanic trick to make men believe in other gods,
I have not done a lot of study in this area but it does seem possible because satan will need to offer some sort of explaination for the missing people - Christians - after the rapture. Please take this with a grain of salt.......