Social housing and environmental enrichment for laboratory animals are powerful refinements that improve welfare and often enhance research quality. Understanding the science drives better implementation.
Social isolation of laboratory rodents is one of the most prevalent and correctable welfare problems in biomedical research. Mice and rats evolved as intensely social species — isolation causes measurable physiological and psychological harm including elevated corticosterone, altered immune parameters, increased aggression on social contact and stereotypic behaviour. These stress-induced changes also confound research results: isolated rodents show different pain thresholds, drug responses and disease progression compared to group-housed animals. Improving social housing therefore serves both welfare and scientific validity simultaneously. The main barrier is institutional inertia and researcher concern about social stress from aggression — concerns that are addressable through appropriate group composition, adequate space and simple environmental modifications.