Turn repetition in pill bugs

Pill bug is an arthropod of about 1 cm in length that lives under fallen leaves and stones. When it turns in an L-shaped passage and encounters a T-maze next, it turns in the opposite direction of the turn in the L-shaped passage mostly. This reaction is called turn alternation. In this paper, we report our experiments to investigate whether pill bugs have a tendency to keep turn alternation or not in a pathway where the distance between the L-shaped passage (forced turn point) and the T-maze (free choice point) is long. Our results suggest that some pill bugs tend to decrease turn alternation, i.e., increase turn repetition, as the distance between the forced turn and free choice points is longer. In nature, these pill bugs may use turn alternation in places where there are many obstacles like stones and dead leaves and do turn repetition in those such as sandy squares with sunlight where there are few obstacles.