The Greys are probably the most well known alien species. They are reported to visit Earth often, abducting people and being witnessed by many. There are two types of Greys reported. One type is known as the intelligent leaders, are up to 8 feet tall with large heads, large dark eyes, long thin legs, arms and fingers, a small mouth and ear holes and two nostrils. They are hairless and appear to communicate without sound via some type of telepathy. Another type of Greys are up to 4.5 feet tall but similar build as the taller ones. These are known as the worker aliens, collecting scientific materials. Both appear to have the same facial structure.