As indicated in the criteria for an animal model of alcoholism (Cicero, 1979; Lester and Freed, 1973), a subject must be willing to work for access to ethanol. Operant procedures allow a researcher to quantify the amount of work a subject will exert in order to obtain access to an ethanol solution. In the present context, work is operationally defined as the amount of lever pressing a subject will display under a fixed-ratio or progressive-ratio schedule greater than 1 (i.e., 1 indicating the subject receives 1 dipper presentation for each lever press). The operant chamber includes a sound-attenuating shell that houses a Plexiglas cage with associated hardware for measuring this work load. The operant test cage [sometimes called a Skinner box after B.F. Skinner who pioneered its use to investigate response contingencies (Skinner, 1971)] generally contains two levers that operate the presentation of a dipper, or sometimes a sipper tube (Cunningham et al., 2000; Epstein et al., 2006; Leeman et al., 2010; Rodd et al., 2004b; Samson, 2000; Samson and Czachowski, 2003) of ethanol or another palatable fluid (e.g., water,
