A new AI tool is revolutionizing the study of paleofeces (fossilized excrement) by enabling scientists to more accurately distinguish between ancient human and dog waste, which are often remarkably similar. Molecular archaeologist Christina Warinner and her colleagues developed this program, which learns from massive datasets of modern human and canine excrement, to re-evaluate past assumptions about ancient diets. This enhanced ability to identify human paleofeces offers new insights into the historical composition of human gut microbiota and provides a more accurate understanding of how ancient diets relate to modern food knowledge and diseases like diabetes.