Laboratory Rodent Enrichment Standards

Mice and rats make up over 90 percent of research animals. Providing adequate environmental enrichment dramatically improves their welfare and the quality of research outcomes.

Key Facts

Mice and rats are the most commonly used research animals globally
Barren cages cause stereotypic behaviors in laboratory rodents within weeks
Enrichment including nesting material reduces corticosterone stress markers significantly
Mice are highly social and suffer in isolation from conspecifics
The 3Rs framework requires refinement of animal use including enhanced welfare

Welfare Considerations

Laboratory rodents kept in standard barren cages show high rates of stress-related behaviors that also confound research results — stressed animals respond differently to treatments. Providing nesting material, hides, and social housing reduces stress, improves welfare, and produces more reliable data. Despite this, many facilities have been slow to adopt enrichment standards. The scientific and ethical cases for enriched housing align, making resistance to improvement difficult to justify.

What You Can Do

Support research institutions that publish animal welfare standards
Advocate for mandatory enrichment requirements in research animal guidelines
Support the development and uptake of alternative research methods
Choose cosmetics and products from cruelty-free certified companies
Donate to organizations improving laboratory animal welfare standards