Rats are among the most used laboratory animals globally. Emerging science on rat welfare reveals the inadequacy of minimalist housing and points toward richer, more positive welfare standards.
Laboratory rat welfare is a welfare challenge of enormous scale and growing scientific urgency. Research on rat empathy, play behavior, and emotional contagion demonstrates these are not simple stimulus-response machines but social beings with sophisticated emotional lives. Individual housing in bare cages — standard practice in many facilities — causes demonstrable psychological harm. Enriched group housing is both the welfare-appropriate approach and, increasingly, the scientifically superior one: stressed animals in impoverished environments produce less reliable research data.