When you see them out in public, they are the ones who give you that fake smile as they walk by you and you feel something is not right. After they pass by, you look back because they will be looking back at you, then stare at their face, smile and you will see their face change for a second to what they really look like. Once they know you can spot them, then they all seek you out too see if it's true! Have fun they are everywhere!