Since the world doesn't believe in God, when the devil and his followers are kicked out of heaven thrown down to the earth they'll interpret them as aliens - because they don't believe in God so they don't believe in demons, so what are they going to call them? Aliens.
Revelation 12:12 (KJV)
Therefore rejoice, [ye] heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
When he is kicked out he knows then he needs to act because by the end of the tribulation he'll be thrown into the bottomless pit for 1000 years (or 1 day).
Revelation 12:12 (KJV)
Therefore rejoice, [ye] heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
When he is kicked out he knows then he needs to act because by the end of the tribulation he'll be thrown into the bottomless pit for 1000 years (or 1 day).