How long do domestic mice and rats live? - briefly
A well‑cared house mouse typically lives 12–24 months, while a domestic rat usually reaches 24–36 months, with exceptional cases extending to about four years.
How long do domestic mice and rats live? - in detail
Domestic mice typically reach maturity within six to eight weeks and live between 1.5 and 2.5 years under proper care. Exceptional individuals may survive up to three years, especially when provided with a balanced diet, regular veterinary checks, and a low‑stress environment. Key determinants of longevity include genetics, housing conditions, nutrition, and disease management.
Rats, most commonly the Norway or fancy varieties, mature by ten weeks and generally live 2 to 3 years. With optimal husbandry—ample space, enrichment, high‑quality protein sources, and prompt treatment of respiratory or neoplastic conditions—lifespans of four years are documented. Factors influencing rat survival mirror those of mice: strain, environmental temperature, cage hygiene, and exposure to pathogens.
Typical lifespan ranges:
- House mouse (Mus musculus): 1.5 – 2.5 years; maximum ≈ 3 years.
- Fancy mouse (Pet mouse): 1 – 2 years; occasional 3 years.
- Norway rat (Rattus norvegicus): 2 – 3 years; maximum ≈ 4 years.
- Fancy rat (Pet rat): 2 – 3 years; occasional 4 years.
Health issues that commonly reduce life expectancy:
- Respiratory infections (Mycoplasma, Sendai virus)
- Tumors, especially mammary adenocarcinomas in females
- Gastrointestinal problems (impaction, ulceration)
- Dental overgrowth due to inadequate chewing material
Management practices that extend longevity:
- Provide a diet formulated for small rodents, supplemented with fresh vegetables and occasional protein treats.
- Ensure cage size allows regular exercise; include tunnels, wheels, and nesting material.
- Maintain humidity between 40‑60 % and temperature around 20‑24 °C to prevent stress.
- Conduct routine health examinations; vaccinate against common viral agents when available.
- Separate sick individuals promptly to limit transmission.
Overall, domestic mice and rats can achieve their species‑specific maximum ages when environmental stressors are minimized, nutrition is optimal, and medical care is proactive.