Disturbances in the neuronal activity of the hippocampal CA2 subregion have been shown to result in impaired social memory in rodents. However, the current assessment of behavioural role of CA2 within the circuit of cognition relies on classical tests, presenting only a snapshot of the behaviour of subjects. As both clinical and preclinical data have revealed a relevance for CA2 in psychiatric disorders such as schizophrenia, it is crucial to uncover the effects of CA2 E/I imbalance in more natural social environments over longer periods of time. Furthermore, gaining a deeper understanding of alterations within the underlying circuit of cognition is essential for the development of future therapeutic treatments.To further characterise downstream effects of an E/I imbalance in murine CA2, CA2 pyramidal neurons were chronically silenced using viral-mediated Designer Receptors Exclusively Activated by Designer Drugs (DREADD) expression. During early adulthood, we performed automated behaviour analysis of individuals in social groups using long-term radio-frequency identification (RFID)-supported video tracking. Moreover, the effects of altered CA2 activity on the global network activity were investigated via whole brain functional ultrasound imaging.Our findings provide a detailed examination of the effects of chronic DREADD-mediated CA2 E/I imbalance on several distinct social behaviours during the light and dark cycle. Additionally, our study contributes to a broader understanding of the global consequences associated with this imbalance.