This is the smallest family of bats in Africa, with only two species in the genus Cistugo. This genus was previously listed in the family Vespertilionidae (Simmons 2005), but recent molecular analyses have demonstrated its ancient origins, having separated from the Vespertilionidae 34 million years ago (Lack et al. 2010). The family is endemic to southern Africa.

Members of the Cistugidae are small bats (mass typically 4–7 g) that share the following characteristics with the Vespertilionidae: the absence of noseleafs, a long tail fully enclosed within the tail membrane (Figure 263), and a conspicuous tragus of variable shape and size (Figure 265 illustrates different tragus designs in the Vespertilionidae). However, members of the Cistugidae can be distinguished from all African vespers on the presence of 2–4 glands in the plagiopatagium (wing membrane) situated posterior to the humerus (Seamark and Kearney 2006; Figure 259b). Cistugo has a similar dental formula to Myotis, both possessing a pair of tiny anterior premolars on each side of the upper jaw, and Cistugo was in fact considered a subgenus of Myotis until relatively recently (Bronner et al. 2003). However, these two genera are cytogenetically distinct, with Cistugo having the karyotype 2n = 50, whereas all Myotis have 2n = 44 (Lack et al. 2010). Practically nothing is known about the general biology of this genus.

Cistugids emit low duty-cycle, frequencymodulated (LD-FM) echolocation calls, at intermediate peak frequencies.

Description: Cistugo lesueuri is a small bat with a mass of around 6 g and very similar in appearance to the smaller C. seabrae. The individual hairs are long and stand away from the body, giving the fur a soft feel. It is dull yellow to yellow-beige above and paler yellow-cream below. The individual hairs are dark at their base and yellowish at their tips. The wings are dark brown with a conspicuous gland present in the membrane on each side. The face is plain, without any noseleafs. The ears are brown and moderately sized, with a long, narrow tragus. The sexes are alike.

The skull is delicate with weak zygomatic arches. In lateral view, the braincase rises slightly above the rostrum, with a smoothly concave forehead. There is a further concavity in the parietal region, owing to an occipital bulge. The sagittal and lambdoid crests are weak or absent. The mastoid processes are not evident in dorsal view.