Last week, Elmer and Karen Kreczmer of Pasadena asked why the water in their toilet moved on windy days. I guessed the wind shook the house and the commode along with it. Seven readers wrote with a smarter explanation. John Stratton, of Catonsville said it best: Wind blowing over the sewer vent pipe on the roof "creates changes in air pressure inside the sewer pipes, which in turn makes the water move back and forth within these pipes," including the toilet bowl. I'm relieved.