The cats licked significantly more often at spouts containing L-Proline at 50 (Wilcoxon, p=0.017) and 500 mM (Wilcoxon, p=0.028) compared to spouts containing water (Fig. 1). This shows that the cats were sampling more extensively from spouts containing the L-Proline at these concentrations than they were sampling the water. However, the registered number of licks was slightly lower at 500 mM indicating a sampling peak at 50 mM. There was no significant difference in the number of licks between L-Proline at 5 mM, 50 mM and 500 mM (Wilcoxon, p>0.05). At 0.05, 0.5 and 5 mM L-Proline, the cats did not significantly differ in the number of times they licked at spouts containing L-Proline compared to spouts containing water (Wilcoxon, p>0.05).

The duration of the cats having their eyes open less than 50% (Fig. 2) was significantly longer when the cats were sampling from spouts containing L-Proline than when sampling water. Similarly, the duration of for how long the cat held its ears positioned upward was significantly longer when sampling from L-Proline compared to water.

The cats were, furthermore, observed to have their eyes less than 50% open for a significantly longer period of time when both when sampling and when drinking L-Proline at 500 mM compared to when sampling or drinking water.

During sampling of 50 and 500 mM L-Proline the cats performed tongue protrusion (Fig. 3) behavior significantly more frequently than with water.