Biology
for House Mouse
With steady food and shelter, house mice breed year-round, driving numbers to high densities that persist for months or even years. Source: https://ipm.ucanr.edu/home-and-landscape/house-mouse/ In a year one female can have five to 10 litters, each usually of five or six pups. Sources vary slightly: pregnancy lasts roughly 18 to 21 days [UC IPM; MU], and the young reach breeding age in about 5 to 10 weeks [UC IPM: 5 to 6 weeks; MU: six to 10 weeks]. Source: https://ipm.ucanr.edu/home-and-landscape/house-mouse/ Source: https://extension.missouri.edu/g9442