Discrimination among odours. A. Relative search densities of ants tested with the training odour (red plots), non-training odours (grey plots), or with the solvent as a control (white plots). Diagram columns, training odours; diagram rows, test odours; dashed line, position of odour; black arrow heads, point of release; sample size, 20 ants per plot. Search plots include the first six turning points after the ants had passed the odour for the first time. For details of graph construction see . B. Median distances between the turning points and the position of odour (dashed line). Box plot: black line, median; box, interquartile range; whiskers, 10th and 90th percentiles, black dots, outliers. Within each plot, diagram letters indicate significant differences (p < 0.01, Dunn's post hoc test) between the groups.