Laboratory rats are among the most numerous research animals globally, and improving their welfare through enrichment has both ethical and scientific benefits, as stress affects research validity.
Laboratory rat welfare represents a significant ethical concern given the enormous numbers involved. Rats are highly intelligent, social animals with complex behavioral needs that standard cage housing fails to meet. The welfare imperative for improving laboratory rat housing is strengthened by evidence that poor welfare - chronic stress from barren, socially isolated conditions - actually compromises the scientific quality of research through effects on stress physiology, immune function, and behavior. Enrichment therefore serves both welfare and scientific validity goals. Institutional Animal Care and Use Committees (IACUCs) increasingly require justification for withholding standard enrichments, reflecting growing recognition that enriched housing should be the default rather than the exception.