Fig. 13. Within a background of horizontal stripes, flies show qualitatively different flight trajectories compared with other visual conditions and fail to localize an odor source. (A,B) Sample flight trajectories and (C,D) mean transit distributions indicate that flies fly curved paths close to the wall. (E—H) Flies respond to odor by reducing altitude, as in Fig. 3. Probability distributions (I) and median segment length (J) shift for animals in odor as in other visual conditions. (K,L) Modulations in collision distance are weak for animals tested in odor. Median segment length and sine fits are determined as in Figs 8, 12.