Body odor was a scent naturally given off by humanoids. Physical exertion could lead to the production of perspiration, which had a distinctive smell. In 2151, Doctor Phlox, fascinated by aspects of Human behavior and biology, discussed his observations with Trip Tucker, noting that Ensign Socorro smelled like a Nausicaan's adrenal gland after she exercised. (ENT: "Fight or Flight") In 2154, Jonathan Archer told Trip Tucker to change his uniform before he stunk up the place. (ENT: "Babel One")