Mice showed no preference for bottle position or spout colour. Control mice (n = 3 for each setup A and B) were implanted with saline-containing pumps for 10 days and then subjected to the two bottle-choice paradigm. Both bottles contained only vehicle (roH2O sweetened with 0.2% saccharine (red)) and the spout was labeled either black or white, as depicted in A and B. Bottles were randomized so that half the mice had their laterally positioned bottle (L) labeled black and half had their medial positioned bottle (M) labeled black. Neither group showed any preference for bottle position or spout color (A: p = 0.13, Wilcoxon rank sum test, n = 3; B: p = 0.60, Wilcoxon rank sum test, n = 3).