Sign-tracking is a model of drug addiction that reveals the underlying secrets of the drug addiction process. Learning about sign-tracking helps us understand how casual drug use can turn into poorly controlled drug-taking that cannot be stopped. The Sign-Tracking model uses procedures that resemble some of the experiences encountered during the ritual of drug-taking. Fundamental to the model is the rewarding experience that drugs can provide. Sign-tracking procedures induce the performance of sign-tracking responses which resemble the poorly controlled actions of the drug addict.