Figure 3.

Experiment 1: Choice between different ramps. Decisions of ants to descend (white bars) or to pass (black bars) at the six ramps that were on offer. Ramp No. 1 was located nearest to the nest; ramp No. 6 was nearest to the position of the feeder and was thus encountered first on the examined homeward runs. The black arrow indicates the ramp that corresponded to the ascending ramp during training. (A) Flat training; (B) Ramp training: a significantly higher proportion of animals descended at ramp No. 6 (p < 0.05, χ² homogeneity test and squared standardized residuals); (C) Λ training. Flat and Λ training: Due to low expected frequencies, no deviation from a uniform distribution could be detected.