What Am I Riddles

Question: Act in my name, and thus remove me. What am I?

Question: I have no wings but I fly,
I have no teeth but I bite.

What am I?

Question: The more you work, the more I'll eat.You keep me full, I'll keep you neat. What am I?

Question:

The dirtier I am, the whiter I get,
Leave a mark on me when you stand, I'll leave a mark on you when you sit.

What am I?

Question: I am the only organ that named myself.What am I?