That has also been my observation, but then, dogs will often react to anything they are unaccustomed to. Try bringing a yard dog inside the house and turning on a ceiling fan sometime!
That's so right. Years ago, we had a small poodle who barked frantically and charged at a large watermelon we had placed on the floor. It really terrified her and she was not a fearful dog. If we touched the melon with a toe and made it rock back and forth, then she really went crazy.