How many pups are born to a house mouse? - briefly
A female house mouse usually produces a litter of five to twelve offspring, with the average ranging from six to eight pups. Litter size can vary depending on factors such as nutrition, age, and environmental conditions.
How many pups are born to a house mouse? - in detail
The domestic mouse (Mus musculus) usually produces a litter of 5 to 8 young. Recorded extremes range from 3 to 12 pups, with the most frequent count falling between 6 and 7.
Reproductive parameters influencing litter size include:
- Maternal age: Younger females (< 8 weeks) often have smaller litters; peak output occurs near sexual maturity (8–12 weeks).
- Nutrition: Adequate protein and caloric intake raise average pup numbers; deficiency can reduce litter size by 1–2 offspring.
- Strain genetics: Laboratory strains such as C57BL/6 tend toward 6–7 pups, whereas wild‑caught populations may vary more widely.
- Environmental stress: Crowding, temperature extremes, and disease lower reproductive output.
Gestation lasts approximately 19–21 days. After birth, the dam nurses the pups for about 21 days before weaning. Females can become pregnant again within 24 hours of giving birth, allowing up to 5–6 successive litters per year under optimal conditions. Consequently, a single female may generate 30–40 offspring annually, although actual numbers depend on survival rates and husbandry practices.