Fig. 9. Flies localize odor within backgrounds of uniformly spaced vertical stripes. Sample flight trajectories from flies flying within arenas of (A) three thick vertical stripes and (B) evenly spaced vertical stripes. Embedding a vial of apple cider vinegar in the floor of the arena (location indicated by white circles) resulted in biased flight trajectories for animals flying within both three-stripe (G) and multiple vertical stripe (H) treatments. Average position indicated with 2-D histograms plotted in pseudocolor. Position bins are 50 mmx50 mm. Number of flies (N) and total flight time in min (t) are indicated for each plot.