Laboratory Mouse Welfare: Housing, Social Needs, and Refinement

Mice are by far the most common laboratory animal, and improving their welfare through better housing, social grouping, and enrichment is a major focus of the 3Rs framework.

Key Facts

Over 100 million mice are used in research globally each year
Mice are highly social animals that suffer when housed in isolation
Standard laboratory caging often prevents natural behaviors like burrowing and nest building
Nesting material is one of the most cost-effective and impactful enrichments for laboratory mice
Group housing reduces stress and produces more consistent research results
Many researchers still house mice in near-barren conditions despite available refinements

Welfare Considerations

Laboratory mice represent an enormous scale of animal welfare impact given the hundreds of millions used globally. Housing mice in socially isolated, stimulus-poor environments causes chronic stress that affects both welfare and research validity. The provision of nesting material, shelters, and group housing are evidence-based refinements that dramatically improve welfare at minimal cost. Despite this evidence, adoption of refinements remains inconsistent across institutions and countries.

What You Can Do

Support organizations like the NC3Rs developing and promoting laboratory animal refinements
Advocate for institutional policies requiring enrichment and social housing for laboratory mice
Donate to research developing alternatives to animal models
Ask universities and research institutions about their 3Rs implementation programs