Figure 3.

A time-dependent preference for a recessed alcove with opaque walls. (A). Diagram of the arena used in this experiment. Four different arena permutations were tested in which the walls of the arena (circular part) and the alcove were either clear or opaque. (B). The mean time spent in the alcove per minute is shown for each of the four arena permutations. No significant differences were found for the two arenas with opaque circles. Flies spent significantly more time in the alcove in the experiment with the clear circle and dark alcove than in the other three arenas (Bonferroni–Dunn; P < 0.001 for all comparisons). There was also a significant effect of time. n = 32 for each arena. Cove = 11.5% of perimeter, cove neutrality = 6.9 sec/min.