JesseTheMutt, I also believe they communicate telepathically due to what many alien abductees claim. However, I do not believe it is the only way they communicate.
I have read many cases where a child would grow up developing relationships with them, where they would 'play hide and seek'. These entities that seem to be with certain 'selected' individuals remain in contact throughout their whole lives. The ones that have these relationships tend to be the 'greys'. I have never come across a case where they communicate verbally. BUT, as Super Pancake said, you do seem to stereotype telepathy with aliens is genral (as it seems). There are many cases where entities which have a completely different nature to the greys are more able to interact on a social level. Not many people know this but there was two crash sites associated with Roswell 1947. Certain individuals who worked for the Government back then were involved in the recovery of these bodies they found at the second crash site. One of the entities from the crash was hiding behind a boulder where he was found and taken in and transfered to Los Alamos (I assume a secret Military Base, most likely underground).
This entity was NOT a Grey! And neither were the other (dead) entities involved in the Roswell Crash. These entities are called EBEN's. People Generalise the Greys too much as responsible for all alien activity. Its rediculous, but totally understandable considering archives of this kind of information is still kept top secret. We are lucky to have an 'anonymous' individual who is carefully releasing some of this information into the public. Here is an extract:
QUOTE
The Grays, which some people characterize as being like the Ebens, were not. They came from a planet near Alpha Centauri A.
[ALPHA CENTAURI is a nearby multiple star with a magnitude of -0.3 and is the third brightest star in the sky. It consists of two yellow and orange stars of magnitudes 0.0 and 1.4. There is also a much fainter third star, an 11th magnitude red dwarf called Proxima Centauri. This is the closest to our Sun, 4.2 light years away or about 0.2 light years closer to us than the two brighter members of the Alpha Centauri system.]
I guess some of you are aware of these entities that are never really given much public attention. This is just one species out of what is said to be seven that are active here on Earth.
Back on topic. Alot of you know of the Alien Humanoids that have long blonde hair, blue eyes; they must be one of the most socially active entities we are aware of to this day. Even though Cases on these entities are very rare (for some reason) they still hold a strong interaction with people (Verbally and Telepathically).
Just some homework for you, please do a google on the name 'Enrique Castillo Rincon. Just one indepth case which I have looked over thoroughly and have come to a conclusion of it being genuine. A 'freindship' with a Nordic alien, I would not like to call it an abduction due to its nature.