The males of Hypsignathus have greatly folded lips, and the males of some genera have erectile hairs on the nape. Two genera of Pteropodidae, Nyctimene and Paranyctimene, have tubular nostrils that open laterally. The members of this family have large, well-developed eyes. Only the genus Rousettus is known to emit ultrasonic sounds during flight, in addition to utilizing its eyes for vision. The penis resembles that of some Primates.
Females have one pair of mammae in the chest region.
The incisors are small, and the canines are always present, even in those forms in which the dentition tends to be reduced. The back teeth are low, elongate, and widely separated. The crowns of the molars are smooth and marked with a longitudinal groove except in Pteralopex and Harpyionycteris, which have cuspidate molars. The dentition is adapted for a soft diet. The palate of the bats of this family generally has eight transverse ridges against which the tongue crushes the food.