How many offspring does a mouse have at one time? - briefly
A mouse usually produces a litter of about five to eight young per birth. Depending on species and environmental factors, litter sizes can vary from three up to twelve.
How many offspring does a mouse have at one time? - in detail
A mouse typically produces between five and twelve pups in a single birthing event. Laboratory strains such as C57BL/6 often average eight to ten offspring, while wild populations may range from four to eight, depending on species and environmental conditions.
Factors influencing the litter size include:
- Genetic background: Inbred laboratory lines are selected for high reproductive output; some wild species, like the deer mouse (Peromyscus maniculatus), exhibit smaller litters.
- Maternal age and health: Younger, well‑nourished females achieve larger litters; senescent or malnourished individuals produce fewer pups.
- Seasonality and photoperiod: Longer daylight periods stimulate higher reproductive rates in many rodent species, resulting in increased pup numbers.
- Nutrition and housing density: Adequate protein intake and low crowding support maximal litter size; scarcity and overcrowding reduce it.
Gestation lasts approximately 19–21 days, after which the female can become pregnant again within a day, allowing multiple litters per year. Consequently, a single female can generate several dozen offspring annually under optimal conditions.