Hundens Hus is Stockholm's largest company within the field of educating dogs and their owners. Among other things they arrange courses in dog obedience, where an increased participation among dog owners across the city would benefit everybody. To create awareness about this, we developed heath sensitive stickers that were placed at adequate hight on strategic spots in town, lamp-posts and house-fronts just to mention a few. The heath sensitive stickers were then exposed to pee from a female dog, which subsequently drove other dogs crazy. When another dog later peed on the sticker, its black color was replaced with the message "Courses in Dog Obedience".