Figure 6.

Experiment 2: Choice between different ramps. Decisions of ants to ascend (white bars) or to pass (black bars) at the six ramps that were on offer. Ramp No. 1 was located nearest to the nest, and was thus encountered first on the examined outbound runs. The black arrow in (B) and (C) indicates the ramp that corresponded to the ascending ramp during training. (A) Flat training; (B) Ramp training: the high number of ascents at ramp No. 6 did not result in a non uniform distribution (p > 0.1, χ² homogeneity test); (C) Λ training. Flat and Λ training: Due to low expected frequencies, a non uniform distribution could not be detected.