Answer:
I can be moved. I can be rolled. But nothing will I hold. I'm red and I'm blue, and I can be other colors too. Having no head, though similar in shape. I have no eyes - yet move all over the place.
I'm not really more than holes tied to more holes. I'm strong as good steel, though not as stiff as a pole.
Hands she has but does not hold. Teeth she has but does not bite. Feet she has but they are cold. Eyes she has but without sight.
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.
I have four legs but no tail. Usually I am heard only at night.
What is always coming but never arrives?