"If we consider that every item has an odor, then, given dogs' olfactory acuity, we can expect that dogs could be trained to tell us when they detect pretty much anything," says Horowitz via email. But researchers have also never forced humans to track hundreds of smells through airports, highways and the Serengeti. Until they do, we don't know the full extent of the Lily and Seamus's smelling super powers. . . or that of Homo sapiens.