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Why are mice and rats commonly used as animal models in biomedical research?

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Three PETA protesters in animal masks and green clothing hold signs reading No Fur at a demonstration against fur in clothing at a shopping district in Seoul, South Korea. — Animal rights A PETA (People for the Ethical Treatment of Animals) demonstration in Seoul, South Korea, against the use of animals for fur in clothing.

Mice and rats are the most commonly used animal models in biomedical research primarily due to their significant biological and genetic similarities to humans. Because they share a high percentage of DNA and possess the same fundamental organ systems, they are susceptible to many of the same conditions and illnesses, such as cancer, heart disease, and diabetes.12

Beyond their biological likeness, these rodents are favored for practical reasons:
* Short Life Cycles: With lifespans of only two to three years, researchers can observe the effects of treatments or genetic modifications across an entire lifespan or multiple generations, which is infeasible with human subjects.32
* Ease of Handling: Their size and temperament make them relatively easy to manage in a laboratory setting.1
* Genetic Manipulation: The ability to create knockout mice—genetically engineered to deactivate specific genes—allows scientists to study the precise role of genes in human disease.31

While these models are essential for scientific progress, their use remains a subject of intense ethical debate regarding the moral status of sentient beings and the necessity of animal testing versus alternative methods.1