Answer:
Long and thin red within with a nail at the end.
People walk in and out of me. They push me and I follow. When they walk out on me I close up and I stay waiting for the next person to walk into my life when I have a more open mind
I am the kind of dog that chases anything red. What am I?
What can you break even if you never touch it?
I'm as simple as a circle worthless as a leader; but when I follow a group their strength increases tenfold. By myself I'm practically nothing.
No matter how little or how much you use me, you change me every month.