• The least weasel becomes sexually mature at 3 months and can reproduce year-round during years of abundance of rodents.

The dwarf weasel, or least weasel, undergoes several distinct developmental stages; during the embryonic stage, the developing offspring receives nourishment from the mother. The young open their eyes between three weeks and one month and one week of age, and begin walking at one month and one week old. The infant stage lasts from one day to two months, where the young live in a den, drink their mother’s milk, and grow rapidly. The species reaches sexual maturity between three and five months of age. The adult stage begins at three months and lasts up to two years and nine months. A typical lifespan ranges from nine years and seven months to fifteen years and eleven months; the maximum lifespan is also from nine years and seven months to fifteen years and eleven months, while the theoretical lifespan extends from four years and seven months to nine years and one month.