in the United States. Established in 1903, under the presidency of Her Majestyâs Minister at Washington, D.C., W.A.F. Baron Gevers, the chamber has promoted commerce between the Netherlands and the U.S. for more than a century.
Complete Physical Maturity: Mice are not done growing until they are between 3 and 5 months of age, depending on the line. Mice should NEVER be bred until they are at least 12 weeks age. If you don't know the line really well, wait until at least 12 weeks, if not longer.wild mice live longer.. around 5 years in captivity, though only around 6 months in the wild due to predators and environmental factors). Maturity: 4 - 8 weeks of age, varying from line to line and mouse to mouse.
This means if you buy a mouse from a pet store, it may very well be pregnant. Mice have a gestation period of 17 to 20 days and can have litters ranging in size from 1 to 20 pups. Those pups then reach reading breeding maturity quickly and, unless segregated into gender-specific housing, can quickly reproduce.