We recognize that our method could not have revealed whether a given stimulus provoked a cyclical pattern of time spent, such as might occur if there were an initial period of avoidance due to neo-phobia followed by an attraction due to curiosity. Only direct observation of the animals will reveal details of the particular responses of the animals to given stimuli. We know too that the long-term effects of exposure to any object would need to be carefully evaluated, and recognize that a given object may benefit, or harm, a rat in ways that are not revealed by the time data used in the present study. Nonetheless, if these concerns can be satisfactorily addressed in future investigations, the provision to laboratory rats of a block of wood for chewing will at the very least occupy their time, and will allow them to exercise a behavior which is fundamental to their nature. The scientist's concern for animal welfare.
Preference tests with rodents to assess housing conditions.
Mental well-being in anthropoids. Noyes Publications, pp 1-11. Animal Suffering . The interpretation of preference tests in animal behaviour . Guttman, HN Ed.