Topher does this too...ever since he was a puppy around an hour or so before bed it seems he gets a 'second wind' and runs through the house like mad...over and under.
For the longest time he used to slide on the floor, unable to stop and run right smack into the side of my filing cabinet..
every single time...lol! And what a noise it would make
CLANG!!! He didn't hurt himself (amazingly so). He'd stop...give his head a shake...and keep right on running!!
My son even piled pillows up against it a couple of times...just like the advertisement on tv...trying to save poor Topher from impact! lol
He's older and wiser now so avoids that area...hehe.
...and yes, it's almost like you can hear him laughing as he runs....not a care in the world of a happy yorkie puppy!