Could E.T be considered terrestrial?

If the same type of beings have been coming to Earth from outside of our planet for as long as we have been here then they are just as terrestrial. How can we be seeded by E.T and they not be considered Earthlings themselves? If "they" have been here before us doesn't that alone make them the first inhabitants? They probably look at us as the late arrivals ruining their planet. They never left when they arrived before human like life evolved. Does that give them claim to living on earth among us?