One afternoon, I was in the backyard hanging the laundry when an old, tired-looking dog wandered into the yard.  I could tell from his collar and well-fed belly that he had a home.  But when I walked into the house, he followed me, sauntered down the hall and fell asleep in a corner.  An hour later, he went to the door, and I let him out.  The next day he was back.
He resumed his position in the hallway and slept for an hour.

This continued for several weeks.  Curious, I pinned a note to his collar:
"Every afternoon your dog comes to my house for a nap.  "

The next day he arrived with a different note pinned to his collar: "He lives in a home with ten children - he's trying to catch up on his sleep."