New research on smell discovered that some smells trigger an automatic terror response, while most are simply left to the brain to savor, identify and react to (be it frying bacon or a bring cloth.) Work is proceeding on finding a smell that be so foul to most people that it would serve as a good riot control, or even battlefield, weapon. The search is difficult because of cultural differences (rural people with no indoor plumbing are used to the smell of shit) and the fact that battlefields are such smelly places that troops eventually become used to the stench. But some excrement based smells apparently do trigger the right panic reaction in nearly all people. By tweaking and testing these promising odors, a truly formidable stench bomb may result, Technically, this would not violate current prohibitions against chemical weapons. However, if the right people get a whiff, this might change.