Laboratory mice are the most widely used research animals globally, and environmental enrichment significantly improves their welfare while often enhancing research validity.
Laboratory mouse welfare represents both a profound ethical obligation and a scientific interest - stressed mice in barren environments are not good models for many human conditions. The gap between current standard practice and achievable welfare is significant: nesting material, shelters, and minimal social housing (where compatible with scientific aims) are low-cost interventions with substantial welfare benefits. Despite the 3Rs framework being widely adopted in principle, implementation quality varies enormously. The welfare case for enrichment is now reinforced by scientific evidence that enriched animals often produce more reliable, generalizable research data - aligning ethics and science.