The male stays with her in her nest. Sometimes people find many voles in a nest together while the voles are mating and raising young. Usually the southern red-backed vole lives alone. Eighteen days after mating, the blind, hairless young are born. They weigh 1.9 g at birth.
Hair appears at eight days.
Their eyes open at 9 to 15 days, depending on how much milk they can get from their mother's eight teats. They drink milk from their mother until they are 17 to 21 days old. They leave the nest when they are only three or four weeks old. Young females can mate when only three months old and give birth when four months old. Males born in March can mate by mid-summer.