Fig. 5. The mean frequency of reverse walking behaviour observed in crayfish for 20 min on the reflective or non-reflective (matte) sides of the test tank. Group-socialized crayfish reverse walked more on the mirrored side of the tank. Both dominant and subordinate crayfish paired for 3 days also reverse walked more on the reflective side compared with the non-reflective side of the aquarium (paired t-test: ^**P<0.005, ^*P<0.05; N=20). Error bars depict standard deviation.