Lab Mouse Social Housing and Welfare

Mice are the most commonly used laboratory animals worldwide. Providing appropriate social housing is one of the most impactful and achievable welfare improvements for this species.

Key Facts

Over 100 million mice are used in research globally each year.
Mice are highly social animals that live in groups in nature and suffer in isolation.
Solo housing ("single housing") causes chronic stress, stereotypies, and altered experimental results.
Many laboratories still single-house mice for convenience despite strong evidence of harm.
Regulatory guidelines in the EU and US now generally recommend social housing as the default.
Paired or group housing reduces anxiety, improves immune function, and enhances experimental validity.

Welfare Considerations

Single housing of mice is one of the most pervasive and unnecessary sources of laboratory animal suffering. Mice are inherently social and experience measurable psychological distress when isolated. Welfare improvements from social housing are not merely ethical but also scientific: stressed animals produce less reliable data, potentially invalidating research findings. Transitioning to social housing requires effort in cage design and management but delivers significant benefits for animals and research quality alike.

What You Can Do

Advocate for institutional animal care committees to enforce social housing as the default.
Support funding for 3Rs (Replacement, Reduction, Refinement) research programs.
Ask universities and research institutions about their mouse housing policies.
Choose to support research programs with strong animal welfare commitments.
Promote awareness among researchers about the scientific and ethical benefits of social housing.