How do mice reproduce and over what period? - briefly
Mice reproduce sexually, with a gestation of 19–21 days resulting in 5–12 offspring per litter, and females can become fertile again about three weeks after giving birth, enabling up to ten litters per year.
How do mice reproduce and over what period? - in detail
Mice reach sexual maturity rapidly; females can conceive as early as five weeks of age, while males become fertile around six weeks. Estrous cycles in females last four to five days, with ovulation occurring during the proestrus phase. Mating typically occurs within a few hours of estrus onset, and a single copulation event is sufficient for fertilization.
Gestation in the common house mouse (Mus musculus) averages 19–21 days. Litter sizes range from three to eight pups, with an average of five. Neonates are born altricial, weighing approximately 1 g and lacking fur and open eyes. They gain weight at a rate of 0.3–0.5 g per day and are weaned between 21 and 28 days postpartum.
After weaning, juveniles attain sexual maturity within an additional two to three weeks. Consequently, a breeding pair can produce multiple generations in a single year. Under optimal laboratory conditions, a cohort can generate up to ten successive litters annually, with each female capable of birthing every 30–35 days when continuously mated.
Key temporal milestones:
- Sexual maturity: 5–6 weeks
- Estrous cycle: 4–5 days
- Gestation: 19–21 days
- Birth to weaning: 21–28 days
- Post‑weaning maturity: 2–3 weeks
These intervals enable mice to sustain high reproductive rates and rapid population turnover.