Exploring social hierarchies: An experimental study using RFID technology in mice

Human societies are structured in a hierarchical manner, be that the work place, government, the playground, or even home-life. Hierarchies are thought to give a system stability; each node within a social network knowing who is above and who is below. However, there is very little experimental research exploring the dynamics of such hierarchies, particularly in animals. This research aims to address this gap using Eco-HAB, a fully automated, RFID-based system, that allows us to study social hierarchies in mice over extended period of time (e.g., 6 weeks). The experiment began with 3 groups of 10 animals. Each group was contained in a separate Eco-HAB until animals formed stable social hierarchies (Phase 1). Then, animals were mixed into groups based on their social rank based on frequency of chasing behaviour in the first phase of the experiment (i.e., all dominant animals; all middle animals; all submissive animals, each group contained in a separate Eco-HAB)(Phase 2). Finally, animals were mixed back into their initial groups (Phase 3). The results suggest that the frequency of chasing behavior can be modulated by social context. However, previous experience and individual differences play a crucial role in determining chasing behavior and social structure.