Enhanced exploratory activity in woodlice exposed to random visuo-tactile patterns

In birds and mammals, randomness is known to have excitatory effects on exploratory behavior, but this phenomenon has not extensively been studied in invertebrates. Four experiments examined the propensity of woodlice (Porcellio scaber) to choose between the exploration of an environment composed of random visuo-tactile patterns and the exploration of an environment composed of regular visuo-tactile patterns. Rearing-up behavior and distance traveled were measured to determine (i) woodlice's reactivity to a forced exposure to random or regular patterns, (ii) the effect of random and regular patterns on exploratory choice, (iii) the effect of random and regular patterns on exploratory choice in preexposed animals, and (iv) the effect of a shelter available in the less explored environment on exploratory choice. The results suggest that random visuo-tactile patterns have an excitatory effect on the exploratory behavior of woodlice and that this effect develops more rapidly if the woodlice were initially preexposed to those patterns. They also suggest that exploration is related to the search for better habitat conditions because the presence of a shelter abolishes that behavior.