What word or phrase does your mother always say?
chemotactic che·mo·tac·tic (kē'mō-tāk'tĭk, kěm'ō-)
Of or relating to chemotaxis.
chemotaxis che·mo·tax·is (kē'mō-tāk'sĭs, kěm'ō-)
The characteristic movement or orientation of an organism or cell along a chemical concentration gradient either toward or away from the chemical stimulus. Also called chemotropism.