Effect of a delay following handling and exposure to a new testing situation on the behaviour of woodlice

Behavioural experiments, whether conducted in the laboratory or in the wild, often involve altering the context for the organisms. Such constraints may include environmental changes or manipulation by experimenters. These disturbances can induce stress, potentially affecting the physiology and behaviour of the animals and thus compromising the initial conditions of the experiment. When stress is directly related to the study subject, it can act as a confounding variable. This study aimed to investigate the impact of introducing an acclimation period, i.e., a delay between handling and the commencement of a task, on animal behaviour, specifically in woodlice. By incorporating this delay, we hypothesised that the animals would return to a baseline psychophysiological state, thereby reducing the stress effects of pre-experimental manipulations. We set up a simple task in which woodlice had to cross a corridor and we manipulated the delay between handling and the task itself. Contrary to our main hypothesis, our findings indicate that acclimation did not significantly affect the speed of woodlice. However, exploratory analyses revealed that a longer pre-experimental delay reduced the likelihood of U-turns in the corridor. Additionally, in trials without U-turns, woodlice spent more time in the experimental apparatus when the acclimation period was longer. These preliminary results only partially support previous research linking stress and exploration in woodlice. Further studies are necessary to confirm these effects and better characterise the relationship between acclimation and subsequent behaviour in scientific experiments.