Who lives longer, rats or mice? - briefly
Rats typically outlive mice, averaging 2–3 years versus 1–2 years for common laboratory mice. This disparity stems from species‑specific growth rates and metabolic demands.
Who lives longer, rats or mice? - in detail
Rats typically outlive mice. Domestic laboratory rats (Rattus norvegicus) reach an average of 2.5–3.5 years, with some individuals surviving up to 4 years under optimal husbandry. In contrast, common laboratory mice (Mus musculus) usually live 1.5–2 years, and rarely exceed 3 years.
Key factors influencing these differences include:
- Metabolic rate: Mice have a higher basal metabolic rate, accelerating cellular wear.
- Body size: Larger mammals generally exhibit slower aging processes; rats are approximately twice the mass of mice.
- Genetic background: Inbred strains of both species show variable lifespans, but rat strains consistently achieve longer maximum ages.
- Environmental conditions: Access to enriched cages, balanced nutrition, and reduced stress extend life expectancy for both, yet the relative gap remains.
Wild populations shorten these figures dramatically. Field studies report average lifespans of 1 year for rats and 0.5–0.8 years for mice, reflecting predation, disease, and resource scarcity. Laboratory data therefore represent the upper bound of potential longevity.
Overall, across captive and natural settings, rats demonstrate a consistently greater lifespan than mice, driven by physiological and ecological variables.