Where do UFO'S come from ?

Where do UFO'S come from?This universe is vast and there are trillions of planets all of which are teaming with life just like this earth planet that we live on.
Altogether there are 14 different levels or worlds.Broadly speaking these are divided into 3 categories,the lower,middle and upper planets.The lower planets are the hellish planets,the middle planets are the earthly planets and the upper planets are the heavenly planets.
There are many different classes of humans that live on all these planets throughout the universe.The demigods live on the upper heavenly planets,the materialistic fruitive workers live on the earthly planets and the demons live on the hellish planets.The demigods experience a far higher standard of material pleasure,thousands of times greater than the pleasure we experience on these earthly planets.The demons mostly suffer because they are materialistic although there are regions known as Bila-svarga or subterranean heavenly planets where the demons that live there experience a high standard of material pleasure.
On these subterranean heavenly planets the demons have beautiful houses and palaces there are nice palatial gardens and parks fully stocked with animals and birds as well as many beautiful plants and flowers.
There is one demon named Maya who lives on a planet known as Mahatalaloka who is a very expert artist and architect. He is also known as a sorcerer and has built many beautiful buildings on these hellish planets.Maya is a member of a race of demons known as danavas and he is also very expert at designing and constructing Vimanas or spaceships that can travel at will throughout the universe.
On these subterranean heavenly worlds the demons who live there do not suffer from disease,nor do they grow old, they keep themselves young by bathing in herbal elixers.
These lower planets do not receive sunlight but are instead illuminated by jewels on the heads of great serpents that live on these planets.
Also the demigods on the upper heavenly planets have very beautiful bodies and live for thousands and even millions of years.It is said that the damsels on the heavenly planets would make the women of this earth look like frogs if such a comparison could be made.
Also the demigods have beautiful airplanes that can not only travel freely on their own planets but they can also travel to other planets as well.
There are also other humans that are known as Siddhas that live on a planet known as siddhaloka.They are born with mystic powers and can travel from one planet to another without the need of any spacecraft.
So there are many races of humans throughout the universe that are capable of space travel but not all of them are friendly.