I want to know what it is called when some one accuses someone else of something the accuser also does. Example: If someone says that it's not ok to eat chicken but does so them self, what is that called?
You can refer to what you are describing as "hypocrisy", and the saying that refers to this context is:
Prov. Cliché You yourself should do the things you advise other people to do.
- Dad always told us we should only watch an hour of television every day, but we all knew he didn't practice what he preached.
(McGraw-Hill Dictionary of American Idioms)