Research and Companion Animal Welfare

Pet Mice and Enrichment in Standard Caging

Mice in standard laboratory and companion caging are frequently housed in understimulating conditions despite evidence that enrichment dramatically improves welfare.

Key Facts

Stereotypic behaviors including bar-gnawing affect up to 60% of mice in standard barren laboratory cages
Provision of a nestbox and nesting material reduces stereotypy rates by over 50%
Mice are highly motivated to build nests — nest-building deprivation causes measurable stress
Group-housed mice show lower stress hormones than individually housed animals across multiple strains
The European Directive 2010/63 requires nesting material as a minimum standard for laboratory mice

Welfare Considerations

Mouse welfare in both research and companion settings is often overlooked because mice are small and inexpensive. However, the capacity of mice for suffering is well-established, and the welfare interventions required are simple and inexpensive. The gap between evidence and practice is primarily one of awareness and prioritization.

What You Can Do

Provide nesting material, nestboxes, and gnawing substrates for all pet mice
Advocate for institutional compliance with enrichment requirements for laboratory rodents
Support the 3Rs framework to reduce the number of mice used in research globally