Environmental enrichment for laboratory animals is a cornerstone of the 3Rs framework. Providing species-appropriate enrichment reduces stress, improves research validity, and fulfils ethical obligations to research animals.
Laboratory animals are entitled to welfare protections that meet their behavioural and physiological needs, regardless of the research context. Barren standard housing has been shown to cause chronic stress that not only harms individual animals but compromises the scientific validity of results — a direct scientific argument for enrichment alongside the ethical one. Nesting material for rodents is now considered a minimum standard, not a luxury. Positive welfare assessment — measuring burrowing, play, and voluntary exploration as indicators of good welfare, not just absence of distress — is increasingly incorporated into laboratory animal welfare frameworks. The 3Rs (Replace, Reduce, Refine) demand continuous improvement in conditions for all research animals.