My daughter's boyfriend's dog Halo is at the house for a few days due to some weather issues.  She's a Jack Russell/Chihuahua mix, small and lithe.
The first day over, he put her in the garage to keep her away from the cats and the allergic person (me). He took a nap before work.
A couple of hours later, she scratched at the garage door, and I let her in. He hadn't turned the lights on, and I expect she was bored.
She trotted down the hall, came back to the kitchen, and spoke to me in body language.
"Hello.  I can't find my boy."
I pointed down the hall and said, "First door on the left."  She raised haunches and lowered her head, "Thank you," and sure enough, she went right there, walked into the room, and looked up to see him sleeping on the bed.
"Yes, I see my boy.  But this is your house."
I said, "Yes, you can get on the bed," and pointed.
Again the thank you nod, and she jumped up and curled up at his side. She didn't move for four hours, and leaves the cats completely alone. She'll stay in whichever room she's told to stay in, patiently awaiting human companionship or instruction.
You can tell a lot about a man by his dog.