How many babies do mice have?

Mice have a very high reproductive rate, which is why a small number of mice can become a large infestation quickly. A female house mouse reaches sexual maturity at about six to eight weeks old and can become pregnant again very soon after giving birth. Each pregnancy lasts about 19 to 21 days, and each litter typically contains five to six babies, though litters can range from three to twelve pups. Under ideal indoor conditions with warmth, food, and shelter, a female can produce five to ten litters per year, meaning a single female could theoretically produce 25 to 60 babies per year, and those babies themselves start breeding within weeks. Newborn mice are hairless, blind, and completely dependent on their mother for about two weeks, after which they grow fur, open their eyes, and begin to explore. By three weeks they are weaned, and by six weeks they can reproduce. In a protected indoor environment without predators, survival rate of pups is high. This rapid breeding cycle is why pest control experts emphasize early intervention, sealing entry points, and using multiple traps at once, because if you only catch one or two mice and leave a pregnant female, the population can rebound within a month.