How environmental enrichment for laboratory mice improves welfare and potentially improves research quality.
Laboratory mouse enrichment represents one of the most tractable welfare improvements in animal research because effective enrichment materials are inexpensive and the welfare benefits are well-documented. The provision of nesting material, shelters, and running wheels to laboratory mice requires minimal facility investment but dramatically improves behavioral health. The concern that enrichment introduces experimental variability is now largely refuted — the bigger source of variability is stress from barren housing. Enrichment as standard rather than special provision should be the baseline in all laboratory mouse facilities.