Soon we might be expecting the presence of unkwon entites known as alien. Alien on a dictionary point of view is:
A person, animal, plant, or other thing which is from outside the family, group, organization, or territory under consideration.
A foreigner residing in a country.
Any life form of extraterrestrial origin.
One excluded from certain privileges; one alienated or estranged.
Now from the perspespective of the whole matter is that aliens are foregin bodies that visit location to learn about the people and also share their experience with others and gain from them