Fig. 4. Training across the artificial hill set-up (compare Fig. 3C), experimental data I (shaving). The top panels show search density plots (abscissae, homing distances; ordinates, cumulated relative search densities between the first and sixth turning points; see Materials and methods). The bottom diagrams display box-and-whisker plots (medians of the initial six turning points), derived from the same data sets (N=15–20 ants for each experimental situation). 0–0, 0–1 and 1–1 are double-digit codes for the particular test situation, the first digit represents the outbound run and the second digit represents the homebound run; 0 denotes the normal situation, 1 denotes the manipulated condition. (A) Animals with the hair plates in their neck region shaved. (B) Animals with the hair plates in the petiole–gaster region shaved. (C) Animals with both neck and petiole–gaster regions shaved.