Freddy, the wiener dog, chases squirrels. The squirrels run up and down the top of our six-foot wooden fence. Freddy growls and runs as fast as he can up and down the yard, but he never catches one. The squirrels actually stop on the fence and squawk at him and twitch their tails. It sounds like they’re laughing at him. Why won’t Freddy chase something that’s slow and on the ground?