Females may breed and raise litters continuously for up to six months if environmental conditions are favorable. Nearly all of the breeding in this species occurs between July and February. Gestation ranges from 13 to 16 days, and litters of up to ten young may be produced. The young first protrude from their mother's pouch at the age of 37 days. They disperse from their natal range when they are 65-69 days old.
Females attain sexual maturity more quickly than males.
They are capable of becoming pregnant when they are 155 days old. Behavior Fat-tailed dunnarts are nocturnal and appear to live in small groups. Although little is known about their social system in the wild, captive study has shown that females are not receptive to the presence of males after they have given birth to a litter. Males housed with females who have litters are often killed by the females. This suggests that females with young may be territorial and solitary in the wild.