Add us to yourGoogle favoritesThe smell of blood is unique, made up of a mix of hundreds of different odor molecules. However, one molecule in particular has caught the attention of researchers: the molecule E2D. This single molecule has the unique ability to attract predators and repel potential prey. This molecule was first identified by researchers from Linköping University in Sweden in 2014, who isolated it from pig blood. “We have now become major predators,” note the researchers, “but naturally, we are not the best predators.”