Do you know that there are more than one kind of alien? Well, there are. People categorize aliens by what they look like. If they are grey, if they look like humans, if they look like reptiles, or anything else. They can come in ALL shapes or sizes. Some aliens are considered 'ancient' because they worked in the military thousands of years ago, and then suddenly left the earth. Let us just say that there are many different kinds of aliens, maybe a little TOO many to believe. Who knows? Maybe there is an alien among you, and you don't even notice.