Common salt (sodium chloride) is essential for life. Animals in the wild sometimes go to great lengths to satisfy their craving for it and we can assume that our early ancestors had similar instinctive needs. This may be the origin of our modern appetite for salt in present day circumstances where it is readily available and is included in many foods for preservation or processing purposes. In any event, the average Western intake exceeds the minimum necessary for survival by a factor of more than 10 to 1, so salt intake is only partially determined by physiological requirements.