How naïve is your naïve subject? The behavior of rodents under a social lens

Rodents, especially rats and mice, are extensively used as animal models in life sciences research, including neuroscience. A big part of the neuroscientific community is devoted to studying animal behavior. Most of the work, however, has been done using paradigms in which animals have to solve tasks alone.Generally, researchers do not take into account the animals' previous history or the situations related to their housing conditions in the animal facility. However, there is ample evidence indicating that the individual experiences lived by a subject have an impact on the brain and the behavior of their cohabitants. At the same time, transmission of information is not unilateral and may impact back to the subject that emits it. In this article, I provide four examples of experimental situations that should be taken into account in experimental designs: social transmission of information between animals from the same home cage, social transmission of information between animals from different home cages (particularly in the case of home cages without lid), hierarchy, and social isolation when isolation per se is not part of the scientific question-. Considering what happens in the home cages in social terms will help to improve experimental designs and align with reduction and refinement principles on humane animal research. Furthermore, including information related to how animals live in the vivarium will help to improve reproducibility, an acknowledged problem in behavioral neuroscience.