Tarsipes is very gregarious in the laboratory, huddling together in groups of two or more. Animals are often caught in a torpid state during cold or wet weather, and presumably huddling helps to minimize body heat loss. Large adult females interact very little with each other and are dominant to males. Females with pouch young have been found throughout the year but predominantly in early autumn, winter, and spring, when pollen and nectar are most abundant. Few young seem to be born in the summer months of December and January.
Some females breed at least twice a year.
Embryonic diapause, such as found in the Macropodidae, also occurs in Tarsipes. Dormant embryos, carried in the uterus while the female is lactating, resume development after the young have left the pouch. The active gestation period appears to be between 21 and 28 days. Litter size is usually 2 or 3, but from 1 to 4 young have been recorded. With a weight of under 5 milligrams each, the young are the smallest known mammalian neonates.