at the bottom of the food chain

At or occupying the position of least importance or influence in a social, corporate, or political hierarchy. As an intern, you're always at the bottom of the food chain, so be prepared to do whatever anyone else tells you to do. You're at a big company now, sure, but you won't be at the bottom of the food chain forever. Man, I'm sick of being at the bottom of the food chain around here. All I do is make copies and get coffee for people!