Laboratory mice and rats represent the vast majority of research animals worldwide, and evidence for the welfare benefits of environmental enrichment is now extensive and robust.
Laboratory rodent welfare has improved significantly through growing adoption of environmental enrichment, driven by scientific evidence that enriched animals are both better off and produce more reliable data. Mice and rats are social, exploratory animals with strong motivations to nest, hide, climb, and investigate novel objects. Barren standard laboratory cages deprive animals of these behavioural needs, causing chronic stress that suppresses immune function, alters stress hormone profiles, and may introduce variables that compromise experimental results. The business case for enrichment is therefore compelling: better animal welfare and better science together. Despite this evidence, enrichment provision remains inconsistent across research institutions, particularly in high-throughput facilities under cost pressure.