It is the largest bat in continental Africa, with wingspans approaching 1 m (3.3 ft), and males are almost twice as heavy as females.

Males and females also greatly differ in appearance, making it the most sexually dimorphic bat species in the world.

The hammer-headed bat is frugivorous, consuming a variety of fruits such as figs, bananas, and mangoes, though a few instances of carnivory have been noted.

Unlike many other bat species that segregate based on sex, males and females will roost together during the day.

The hammer-headed bat is sometimes considered a pest due to its frugivorous diet and its extremely loud honking noises at night.

Hypsignathus Epomops Nanonycteris Epomophorus Micropteropus Megaloglossus Myonycteris Lissonycteris The hammer-headed bat was described as a new species in 1861 by American scientist Harrison Allen.

T. S. Palmer speculated that Allen chose the name Hypsignathus to allude to the "deeply arched mouth" of the species.

[8] A 2011 study found that Hypsignathus was the most basal member of the tribe Epomophorini, which also includes Epomops, Micropteropus, Epomophorus, and Nanonycteris.

[13] Other differences between the sexes relate to their social system, in which males produce loud, honking vocalizations.

Therefore, males have greatly enlarged larynges, about three times the size of females',[14] extending through most of the thoracic cavity, and measuring half the length of the spine.

[12] These numerous adaptations caused scientists Herbert Lang and James Chapin to remark, "In no other mammal is everything so entirely subordinated to the organs of voice".

[15] Males overall have boxy heads with enormous lips, while the females, with their narrower snouts, have more foxlike faces.

[14] Males and females both have dark brown fur, with a paler mantle (sides and back of neck).

It is suggested that fruit bats compensate for this by possessing a proportionally longer intestine compared to insectivorous species.

[12] Van Deusan (1968) reports H. monstrosus showing some carnivorous behavior by attacking chickens to drink their blood and scavenging for meat.

Females may become pregnant up to twice per year, giving birth after five or six months gestation[12] to one offspring at a time,[14] though twins have been reported.

[12] Each male claims a display territory of about 10 m (33 ft) in diameter,[13] in which he honks repeatedly and flaps his wings while hanging from a branch.

[20] Males display for around four hours before foraging, with peaks in lekking activity in the early evening and before dawn.

The chosen male emits a "staccato buzz" call, followed immediately by copulation, which lasts 30–60 seconds.

[12] In the before-dawn peak in activity, copulation is less frequent, and males spend time jockeying with each other for the best display territory.

[22] During the day, the hammer-headed bat roosts in trees, typically 20–30 m (66–98 ft) above the ground in the forest canopy.

While roosting, individuals in a group are approximately 10–15 cm (3.9–5.9 in) apart, with males on the periphery and females nearer the center.

[24] Its ability to produce extremely loud vocalizations means that some consider it one of Africa's most significant nocturnal pests.

[28][29][30] Megabats like the hammer-headed bat tend to be over-sampled relative to other potential Ebola virus hosts, meaning that they may have an unwarranted amount of research attention, and as of 2015[update], no bat hunter or researcher is known to be the index case ("patient zero") in an Ebola outbreak.

In captivity, hammer-headed bats, particularly males, are vulnerable to stress-related illness, especially when moved or placed in new enclosures.