Our home has a center chimney and traffic flows through rooms and hallways surrounding it.
One evening I am in the sitting room reading the paper and the kids are just running circles through the house. I was too absorbed in the newspaper to notice at first, but eventually they started panting and sweating, which got my attention.
I asked them "What are you doing?" and they both said in unison "Running too much. Have to get sleepy. Ate too much sugar."
Apparently they had raided the cookie jar when out backs were turned.