Aliens are humans in a more advanced stage of evolution.
People who work at a computer will become smaller and thinner from lack of sunlight and
exercise. This will also cause the skin to pale and take on a grayish color. Since these
people have to use their brains more than anything their heads and eyes will become larger.
Also fingers will elongate for typing ease. These are the classic features of what people who have been abducted say the aliens look like.
This will happen to “texters”, people who text on their cell phones or blackberries or whatever small hand held devices they use, but the process may work backward. Fingers and eyes will change into what I have described above before the body, head and skin color will because of mobility of the devices.
In both cases, the mouth will shrink because of lack of use. Why have a big mouth if
one doesn’t need it? Noses will also shrink faster on computers users since they don’t  move around as much as mobile device users.
With all of this, I believe that telepathy will come into play, since communication verbally
will become obsolete.
One may wonder why “aliens” abduct humans for experiments. Here is what I think:
1. A disease is destroying them and the aliens need the human DNA to fix it.
2. Reproduction may be another reason. The use of sperm and eggs may be needed to mix with whatever they have to make more of themselves.
3. I would think that mental state would be a factor in the aliens’ development of
psychic abilities.
These could be the reasons why some people claim to have been taken multiple times, and others are only abducted once or not at all.
Aliens have been a part of the human culture for a long time. It is evident that something has been coming to Earth (or back to Earth) because of certain structures and what they represent, i.e. Stonehenge and the Pyramids.