Laboratory mice benefit substantially from environmental enrichment that supports their natural behaviors, reduces stress, and improves both welfare and research reproducibility.
Laboratory mice — among the most widely used research animals globally — typically spend their lives in barren plastic cages that prevent expression of almost all natural behaviors. Evidence now clearly shows that enrichment such as nesting material, shelters, running wheels, and social housing improves welfare while simultaneously improving research quality by reducing stress-induced physiological and behavioral variability. Regulatory frameworks increasingly require enrichment provision, but implementation varies widely. The case for enrichment is compelling on both ethical and scientific grounds: mice are sentient, capable of suffering and positive experience, and enriched animals are better models for understanding mammalian biology.