Fig. 2. Detour vectors associated with the barrier in the training orientation. (A) Vector ants (left side N=9, right side N=10) were released at the fictive position of the feeder relative to the barrier (5 m south of the tip of the barrier). (B) Zero-vector ants (left side N=13, right side N=12) were released at the tip of the V-shaped barrier. The green arrows point towards the fictive position of the nest relative to the barrier (
). The fictive position of the nest relative to the home vector of the ant coincides with in A and is located at the tip of the V-shaped barrier (the release point) in B. The normalised path density histograms were obtained by determining the path lengths of the detour vectors in squares of 0.5 mx0.5 m. These values were then assigned to seven classes ranging from 0 % (white) to more than 1.5 % (red) of the total path length of the detour vectors at each of the ends of the barrier.
