“We are part of a symbiotic relationship with something which disguises itself as an extra-terrestrial invasion so as not to alarm us.”
“Increasingly I felt as if I were entering a struggle that might even be more than life and death. It might be a struggle for my soul, my essence, or whatever part of me might have reference to the eternal. There are worse things than death, I suspected… so far the word demon had never been spoken among the scientists and doctors who were working with me…Alone at night I worried about the legendary cunning of demons …At the very least I was going stark, raving mad.”
– Whitley Strieber, Transformation, p. 44-45
“That which is above is the same as that which is below”
– Egyptian Emerald Tablet
Our Subterranean Environment
The subsurface of Earth is filled with passages. The U.S. alone has 40,000 known caves as of 1988, and 360,000 others without openings to the surface, but are also estimated to exist. 
Some known caves extend as far as 300 miles underground. This does not include passages that are too small for humans and continue many miles deeper. Many of these “voids” contain water, air, chemical gas and fluid mixtures.
Most interestingly, one must wonder whether a perfect mix of subterranean conditions (air and water) can exist to create an ecosystem where life forms can evolve and exist.
On the surface of the Earth, life forms depend on solar energy. However one such isolated living eco-system was found in a Romanian cave which included land life forms which depended on chemical reactions exclusively for sustenance (not solar energy).
The eco-system developed in only 5.5 million years of isolation – the only requirements are oxygen from the surface. The life forms in this particular ecosystem were very small, and included “simple bugs”: millipedes, centipedes, mutant scorpions, leeches, spiders, springtails, pillbugs, and bristletails. 
At nearly 1.8 miles under the surface of the Earth, life can be found thriving at about 75 deg. C / 167 deg F. Scientists suspect that microbes may exist up to 2.4 miles under land, and 4.2 miles under sea. It is suspected nothing lives deeper than that because of temperatures reaching over 113 degrees C.
Theoretical Evolution of an Intelligent Subterranean Life Form
It is difficult to theorize what a larger intelligent life form might look like if it exists underground in such an environment as described above, and would be largely speculation without existing similar life forms to examine.
One could safely assume that the evolution of such life forms would involve an adaptation to deal with higher temperatures, the need to burrow, navigational difficulties, and an acrid environment consisting of various gas and liquids.
To do this, we’ll examine briefly the biology of two subterranean mammals – the blind mole rat, and the naked mole rat.
To overcome the problems involved in navigation without landmarks, the blind mole rat has adapted to navigating by relying on the Earth’s geomagnetic field.
In essence, evolution has provided these particular life forms with the ability to “tune” into the earth’s magnetic field, and in effect “sensing” direction.
“Here we show through two path integration experiments (homing and shortcut finding) that the blind mole rat assesses direction both through internal signals and by estimating its heading in relation to the earth’s magnetic field. Further, it is shown that the greater the circumvolution and length of the travelled path, the more the animal relies on the geomagnetic field. This path integration system strongly reduces the accumulation of errors due to inaccuracies in the estimation of rotations and thus allows the mole rat to navigate efficiently in darkness, without the help of any landmark, over both short and long distances.” 
The naked mole rats, also subterranean life forms, have adapted to such an environment in various way as well.
“The Naked Mole-Rat is morphologically characterized by its mostly hairless translucent skin and prominent incisor teeth. Naked Mole-Rats have some hair between their toes which they use to sweep dirt. It also has whiskers on both face and tail for navigating subterranean habitats as it is nearly sightless. The skin appears wrinkled because the Naked Mole-Rats are devoid of subcutaneous fat. Naked mole-rats are the only known poikilothermic mammals, that is, their body temperature is variable and related to ambient temperature. These animals have developed physiological mechanisms to withstand thermal variations, including the lack of cutaneous sweat glands, as well as behavioral mechanisms, such as burrowing and huddling.”
Greys as Subterranean Life Forms
Given the clues above regarding typical evolutionary “mutations” allowing life forms to live underground, we will now examine the typical description of “greys” as the common elements found in most abduction and sighting descriptions.
For this description, I will use the detail provided by Colonel Philip J. Corso in his book “Day after Roswell” (chapter 7).
While there is not sufficient evidence to suggest that this is the most accurate description (or even real), it does at least match most elements of the descriptions provided by various witnesses over time who have claimed to have seen the “greys”.
While reading these features, compare them to the various evolutionary adaptations shown above for the existing mammals that we know of that live a mostly subterranean life. I’ve highlighted the most significant.
• The head is large by human standard.
• Eyes are generally slanted, large and black
• Nose is usually vague. 2 small “holes” are visible
• Mouth is indicated by a small slit without lips, this appears to be non-functional
• No teeth in the mouth cavity
• The body and head are completely hairless
• Torso is described as small and thin, often covered in a “metallic” garment
• Arms are long and thin, and reach to the knees
• Reports of the fingers vary from 3 to 4, long webbed, and possibly with a claw or fingernail
• The brain is larger than ours and has more than 2 lobes, possibly 3. The third lobe is thought to be used for telepathic communication
• Skin description ranges from light tan to the pasty grey color
• Texture is described as scaly or reptilian in nature. No muscle or skeletal structure is visible
• No external reproductive genitalia, possible reproduction by a cloning method
• No discernible digestive tract found, but a 2 piece organ that seems to be a combined heart and lungs organ. Digestive functioning is believed to be through the skin in a form of osmosis
The highlighted features above could very easily be construed to benefit a life form that lives in a subterranean environment.
If absorption of food is through the skin, the mouth and teeth would become unnecessary as well as any substantial digestive tract, since most sustenance would come from fluid.
Due to high temperatures, hair would become unnecessary and from lack of solar exposure, skin color would be “pasty” or grey – even eventually becoming scaly and reptilian in nature.
Long arms as well as webbed hands and feet would aid in digging and burrowing as well as managing in some almost completely aquatic environments. A shorter height would allow easier movement through much smaller caverns and crevices.
Furthermore, as displayed by the blind mole rat, it’s very possible that the evolutionary process could instill a much stronger sense in these life forms of the earth’s geomagnetic field. And if of a higher intelligence, they would be more capable of determining methods to better utilize such geomagnetic forces for developing the ability for aerial flight above the surface – as opposed to the use of aerodynamics as developed by surface-bound humans.
Legends of Subterranean Life Forms
There are quite a few stories of strange happenings in and around the deep caves and caverns of the world. I will share one of the most fascinating with you. If interested, I suggest taking a trip to Malta to doing some exploring for yourself, if you have the funds and if you have the nerve.
On the Island of Malta, there is an area of deep catacombs that extend far down into the earth.
This, according to certain sources, was the subterranean passage and chamber which was referred to years ago in an article which appeared in the August, 1940 issue of the NATIONAL GEOGRAPHIC Magazine.
The article stated the following concerning several people who disappeared in these catacombs without a trace:
“Many subterranean passageways, including ancient catacombs, now are a part of the island’s fortifications and defense system. Supplies are kept in many tunnels; others are bomb shelters. Beneath Valletta some of the underground areas served as homes for the poor.
Prehistoric men built temples and chambers in these vaults. In a pit beside one sacrificial altar lie thousands of human skeletons. Years ago one could walk underground from one end of Malta to the other.
The Government closed the entrances to these tunnels after school children and their teachers became lost in the labyrinth while on a study tour and never returned.”
Before and after this event, an employee of the British embassy had visited the site and later wrote about it.
One article written by a Miss Lois Jessup, at the time an employee of the British embassy and later secretary for the New York Saucer Information Bureau (better known as NYSIB), appeared in an old issue of Riley Crabb’s BORDERLAND SCIENCE magazine, published by the Borderland Sciences Research Foundation (B.S.R.F.) and was later reprinted in full in Dr. Allen’s book ENIGMA FANTASTIQUE.
Miss Jessup claimed that she visited Malta and the Hypogeum also, once before the tragic disappearance of the children, and shortly thereafter.
She described how on her first visit to the catacombs she finally convinced the guide to allow her to investigate one of the so-called “burial chambers” near the floor of the last chamber in the third sub-basement, the supposed “end” of the Hypogeum tour.
He seemed to know something she didn’t, but finally consented and told her that she could enter at “her own risk”. 
In her own words (quoted from source):
“What’s down there?” she asked the guide, pointing to a small opening off the walls. “Go there at your own risk, and you won’t go far,” he replied. This was a challenge Lois couldn’t pass up. She talked it over with her friends. Two of them decided to stay with Joe. The other three summoned up enough courage to explore with her. “I was wearing a dress with a long sash that day and as I decided to lead the group I asked the fellow behind me to hold onto it. So, with half-burnt candles in our hands the four of us started through that low, narrow passage, groping and laughing our way through. ” I came out first, of course, onto a ledge pathway only two feet wide, with a sheer drop of fifty feet or more on my right and the wall on my left.
I took a step forward, keeping close to the rock wall side. The person behind me, still holding on to my sash, was still in the tunnel. “I held my candle higher and peered down into the abyss, thinking that with this dangerous drop it was better not to go on further without a guide. Then I saw about twenty persons of giant stature emerge from an opening deep below me. They were walking in single file along another narrow ledge down below. Their height I judged to be about twenty to twenty-five feet, since their heads came up about half way on the wall on the opposite side of the cave. They walked very slowly, taking long strides. Then they all stopped, turned and raised their heads in my direction. All simultaneously raised their arms and with their hands beckoned to me.
The movement was something like snatching or feeling for something, as the palms of their hands were turned down.” By this time her friends back in the passage were becoming impatient of the delay. There was a tug at the sash. “Go on. We’re all getting stuck in here. What’s the matter?” “Well,” stammered Lois, “there’s nothing much to see.”
She took another hesitant step forward, her candle in her right hand, her left hand against the cold rock for support. but it wasn’t on a cold rock wall, it was on something damp and wet, AND IT MOVED! “Then a strong wind came from nowhere and blew my candle out! Now I really WAS scared in the darkness. I yelled to the others, “GO BACK! GO BACK! Guide me with my sash. I can’t see!” “They pulled me back into the low tunnel and we backed up all the way along the passage into the larger room.” Lois was relieved to see her friends and Joe, the guide, again. “Did you see anything?” one of them replied. “No, my candle went out,” she replied with finality. “There was a strong draft in there.” “Let’s go,” said Joe, looking at Lois, and she returned his glance eye for eye.
She knew beyond any shadow of a doubt that at one time Joe had also seen those giants. There was an expression of caution in his glance which held her to silence. “Out in the hot Malta sunshine again we thanked our guide and as we tipped him Joe said to me: “If YOU really are interested in exploring further it would be wise to join a group. There is a schoolteacher who is going to take a party exploring soon.” Lois left her address with him, suggesting that he have the schoolteacher get in touch with her; but she never heard any more of it.
Some few days later one of the friends of the Hal Saflieni excursion called her on the phone. “Remember that tunnel you wanted to explore in the Hypogaeum?”
Well, it says here in the local paper that a schoolmaster and thirty students went exploring and apparently got as far as we got. They were roped together, with the end of the rope tied to the opening of the cave. As the last student turned the corner where your candle blew out the rope was clean cut. None of the party was found because the walls caved in.” Miss Jessup was shocked by the news, but it only strengthened her own resolve to say nothing of what she had seen and felt that unforgettable day in Hal Saflieni. 
“It was asserted that for weeks afterwards the wailing and screaming of children was heard underground in different parts of the island, but no one could locate the sources of the cries.
As for the Catacombs beneath Malta itself, there are some ancient accounts which say that deep caverns beneath the island continue underground BEYOND the shores, and according to one source [i.e. the ever elusive “Commander-X”], part of this labyrinth stretches hundreds of miles northwards and intersects with catacombs beneath Rome (the hill Vaticanus?) or at least did so in ancient times…” 
Visiting the Caves of Malta
You can view a layout of the officially recognized areas of the caverns, as well as click on the rooms to see photos: http://web.genie.it/utenti/m/malta_mega_temples/hypo/plan.html
In this archeological paper on the site, one of the carvings is described as follows. Compare the similarities of this drawing to the descriptions discussed in the first part of this article:
“The wall at its back contained a shallow segmental-headed recess which occupied almost all the available space and served as a backdrop to a bust length relief carving of a humanoid figure with a tall neck and an elongated, pear-shaped head (fig. 3). It has large almond-shaped eyes, a prominent nose, a heavily lipped mouth and an accentuated chin. Both arms are represented. One hangs limply by the side of the body while the other is folded at the breast.”
Are Life Forms Living Under Our Feet?
There exists the distinct possibility that advanced life forms could exist deep under the crust of our planet earth.
This assumes a completely different species of sorts, which has adapted through the course of evolution to the different environment of subterranean life. These adaptations would give them more of a thin, insect-like or even a reptilian look, and would give them features which would seem quite alien to humans.
If such intelligent life existed below the surface of the earth, one could assume that if they did in fact develop a form of travel above the surface, and if it was through flight, it is very likely it would involve use of the earth’s geomagnetic energies which this particular species would be much more in “tune” with than surface dwellers.
These beings could have been here for many thousands of years, and could very likely be much more advanced than the surface-dwellers. It also suggests that interactions with humans could have been taking place for just as long – and many of the mysterious wonders of the past civilizations which have disturbingly disappeared from existence, might be explained by clues found in the very ground under our feet.
Editor’s Note: This article was previously published at RealityUncovered.com, which no longer operates. The original author was Ryan Dube
 Cave, page 332, McGraw-Hill Concise Encyclopedia of Science and Technology, Second Edition, McGraw-Hill Publishing, 1989, 1984
 Deep Dwellers BY RICHARD MONASTERSKY, Science News Online , http://www.sciencenews.org, March 29, 1997
 A subterranean mammal uses the magnetic compass for path integration – Tali Kimchi,*† Ariane S. Etienne,‡ and Joseph Terkel* Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel; and ‡Faculté de Psychologie et des Sciences de l’Éducation, Université de Genève, 40 Boulevard du Pont d’Arve, 1205 Geneva, Switzerland