Association between visual cues and time of day in an ant

On the basis of what is known about the biology and the cognitive abilities of the workers of the ant Myrmica sabuleti studied at a collective level, we wondered if these ants could associate sighted cues with time periods of the day. Working on four colonies and using four different cues, we showed that, trained to one kind of cue from 8 to 19 o’clock and, at the same time, to another kind of cue from 20 o’clock to 7 o’clock the next day, the ants responded far more to the first kind of cue at 16 o’clock and far more to the second kind of cue at 4 o’clock. Thus, they not only learned the conditioned stimuli but also associated them with the time of day during which the conditionings were performed. Results of previous experiments on quantitative sequences rule out the possibility that the present findings could be explained by an aversion to less recently learned cues. Associating environmental cues to particular times of the day should allow ants to best adapt their behavior to their habitat.