Little is known about reproduction in hammer-headed bats. In some populations, breeding is thought to take place semi-annually during the dry seasons. The timing of the dry season varies depending on the locality, but in general the first breeding season is from June to August and the second is from December to February. Females may become pregnant up to twice per year, giving birth after five or six months gestation to one offspring at a time, though twins have been reported. Newborns weigh approximately at birth. Females reach sexual maturity faster than males, and can reproduce at six months. Females reach adult size by nine months of age. In contrast, males are not sexually mature until eighteen months. Males and females are similar in size for their first year of life.