Answer:
Big as a biscuit, deep as a cup, but even a river canβt fill it up. What is it?
What travels from house to house and is sometimes narrow and sometimes wide but always stays outside?
Lighter than what I am made of, More of me is hidden Than is seen.
What wears a coat in the winter and pants in the summer?
We are five little objects of an everyday sort. You will find us all in a tennis court.
I'm the source of all emotion but I'm caged in a white prison.