Laboratory mice are the most numerous research animals globally, and enrichment provision significantly improves welfare while also improving research validity through reduced stress-related physiological variation.
Laboratory mouse welfare is significant both as an ethical obligation and a scientific imperative - stressed mice in barren cages show physiological and behavioral variability that compromises research reproducibility. The dual benefit of enrichment, improving both welfare and research quality, creates a compelling case for adoption that transcends welfare advocacy alone. Nesting material, social housing, and shelter objects are low-cost, high-impact interventions whose adoption should be universal in well-managed research facilities.