After about six months their boss comes up to them and says that he is very pleased with their work, that they're exemplary emloyees and that he is very happy to have them. He also says that the cleaning lady has vanished a couple of days ago and asks if they happen to know anything about that.
"No sir" says the head canibal.
"OK" says the boss and leaves them be.
"Alright" says the head canibal when the boss has left "Who did it?!"
"I did!" one of them admits.
"You idiot! We've been having fifty different types of manager in the past six months and nobody batted an eye! You had to eat the one person in this office that actually gets any work done!"