Rodent Welfare in Laboratory Research

Mice and rats constitute over 90% of research animals globally, with welfare improvements through refinement of procedures, housing, and handling offering major benefits at scale.

Key Facts

Approximately 100 million mice and rats are used in research annually worldwide.
Standard laboratory housing — small, barren cages — causes chronic stress detectable through behaviour and physiology.
Tunnel handling reduces mouse stress significantly compared to tail lifting in research settings.
Environmental enrichment including nesting material and shelters reduces abnormal behaviour in laboratory rodents.
Stress from poor housing and handling can confound research results, making welfare improvements also scientifically valuable.

Welfare Considerations

Laboratory rodent welfare represents one of the highest-impact opportunities for welfare improvement by number of animals affected. Refinements including tunnel handling, enriched housing with nesting material, same-sex group housing, and pain assessment using facial coding are evidence-based, cost-effective, and improve both welfare and data quality. The alignment of welfare improvements with scientific validity creates compelling incentives beyond ethics alone. Institutional 3Rs committees that champion refinement are the primary driver of welfare improvement in research settings.

What You Can Do

Support research institutions with active 3Rs programmes and published refinement commitments.
Advocate for mandatory enriched housing standards for laboratory mice and rats.
Support organisations developing non-animal research alternatives to enable replacement.
Choose to purchase products from companies with published cruelty-free research policies.
Engage with your institution's 3Rs committee if you work in research settings.