Answer:
I run around the city, but I never move.
Fatherless and motherless. Born without sin, roared when it came into the world. And never spoke again.
I have a neck but no head. I have a body but no arm. I have a bottom but no leg.
In we go, out we go. All around and in a row. Always, always steady flow. When we'll stop, you'll never known. In we go, out we go.
It doesn't live within a house, nor does it live without. Most will use it when they come in, and again when they go out.
When is it bad luck to see a black cat?