The kitchen Table and the Dog's Tail

Porter (3) loved to play with our dog, Buster. He would grab onto the dog's tail and the dog would take off with Porter hanging on following where ever the dog went. It only took the dog a couple of days to figure out how to stop it. Running full tilt with Porter hanging on the dog headed under the kitchen table. Porter's eye level was below the table so he didn't even realize Buster was setting him up. You guessed it- at full speed Porter followed the dog and hit his forehead on the bottom of the table knocking him out. Porter's a quick learner and it only took once.