I don't know about aliens living amongst us. It could be real. I am sure there have been plenty of intelligent lifeforms with the desire to relocate to other habitable worlds. Earth can serve as such an destination.
However, I am more inclined to believe that ancient earthlings are a more likely candidate for the role of
OTHERS living amongst us.
I am talking about some sort of humanoid type that thrived on the earth 100,000 years ago or 500,000 years ago that doesn't want to be in open contact with the rest of us present day homosapiens.
They could be an ancient population that sought protection underground from an ancient global calamity. We could be the descendents of those the were not of their group. Or we could be the descendents of a group that left the original group to replenish the population-us. Of course this is just speculation.
Of course, their technology would be so advanced compared to ours. Electricity is still new to us.
What we assume to be spacecrafts can simply be advanced aircrafts with little of no ability to travel interplanetary. Their technology, like our own, wouldn't require THE OTHERS to travel across the great expanse of space to abduct us or to harvest body parts from our livestock. Everything they would need is already here.
They would have a similar build and similar physiological needs as us like oxygen and water. They may view us a primative and domesticated breed of humanoid that they can interact whenever and however they chose.
The Others would be suited to life on earth. They could breath the air, drink the water, eat our foods and even know our languages and cultures.
They could live in a large underground network of cities. We currently have the technology to make my speculations about The Others a reality.
China has a bunker capable of sustaining 200,000 people.
http://www.worldwatch.org/node/4424
Shanghai Completes Massive Underground Bunker to Protect Citizens from Disasters
by Zijun Li on August 8, 2006
Shanghai’s Civil Defense Office recently announced completion of the city’s largest subterranean bunker, spanning an area of over 90,000 square meters, reported Shanghai Morning Post. The massive underground shelter is able to accommodate 200,000 citizens at a time, offering protection from ground-level disasters such as nuclear radiation, poisonous gas releases, or terrorist blasts.
According to Shanghai Morning Post, 15 tunnels, each of which stretches 4,000 meters, link more than 10 trading centers, office buildings, and residential buildings throughout the city. The complex is equipped with its own power supply, ventilation, and power storage capability, which is able to ensure a daily underground supply for 1–2 weeks. The shelter is also well connected to ground-level railway transportation from southern Xingzhuang region to northern Baoshan, providing flexibility to those seeking refuge from disasters. During non-emergencies, portions of the underground bunker could potentially be used as a commercial garage or storehouse.
