As a professional animal trainer, Lori Andersen was disturbed when her own dog developed a bad habit. Every time she hung her wash out on the clothesline, the dog would yank it down. Drastic action was called for. She put a white kitchen towel on the line and waited. Each time the dog pulled it off, Lori scolded her. After two weeks the towel was untouched. Then she hung out a large wash and left to do some errands. When she came home, the clean clothes were scattered all over the yard. On the line was the white kitchen towel.