In this study, mice from S9 had 4 days of ethanol access (2 hours on Days 1–3, 4 hours on Day 4), with separate groups of animals having a single ethanol bottle (standard DID) versus two bottles (ethanol vs. water). An initial analysis compared placement of ethanol tube (left vs. right) on intake on Day 4 for mice whom the ethanol tube was placed in the position of the water bottle versus mice for whom ethanol was placed on the other side of the cage top. Placement of the ethanol tube did not significantly alter ethanol intake in either the standard DID group [F(1,16) = .03, p = .86] or the two-bottle choice group [F(1,18) = .45, p = .51]. Thus, data for the counterbalanced groups were combined for analyses of intake (see Figure 6). Mean BEC in the single-bottle group was .47 mg/mL and average intake on the last day of testing was 4.91 g/kg ethanol. Mean BEC in the two-bottle group was .12 mg/mL, and intake averaged 2.98 g/kg. BEC and ethanol intake differed significantly in the single-bottle
