Number of lateralized (L: Left; R: Right) and non lateralized (N: Neutral) individuals found in each population.

Lateralization Index (LI) = (right runs−left runs)/(right runs+neutral runs+left runs). Left% and Right% represent the percentage of times that all the lateralized individuals (left and right) chose the left or right refuge. Fisher exact test P two-tailed was used only with lateralized individuals, in order to test if left- and right- lateralized individual were equally common at population or species level (see also Figure 2).