Laboratory animal enrichment has advanced significantly beyond regulatory minimums, with evidence showing that enriched housing improves both animal welfare and scientific reproducibility.
Laboratory animal enrichment has moved from nice-to-have to scientific necessity, as evidence accumulates that stressed, bored animals in barren cages show abnormal physiology and behaviour that compromises experimental validity. Mice given nesting material show better thermoregulation, reduced anxiety, and more natural behaviour. Rats group-housed with environmental complexity show more robust and reproducible results in neuroscience experiments. The welfare and scientific cases for enrichment are aligned, creating an incentive for laboratories to go beyond regulatory minimums. Institutions that invest in enrichment benefit from improved animal welfare, better science, and reduced variability in their results.