Wikipedia
The Nycteridae comprise a family of bats commonly called slit-faced or hollow-faced bats. They are grouped in a single genus, Nycteris. The bats are found in East Malaysia, Indonesia, and many parts of Africa.
They are small bats, from 4 to 8 cm in body length, and with grey, brown, or reddish fur. A long slit runs down the centre of their faces from between the eyes to the nostrils, and probably assists in echolocation. They have large ears, and a complex nose-leaf. Their tails end in a T-shape, formed from cartilage, a unique feature among mammals. Their dental formula is:
Slit-faced bats roost in caves, trees, and buildings, typically in fairly small colonies. Some even roost in animal burrows, such as those of hedgehogs or porcupines. They eat insects, and some terrestrial invertebrates, such as spiders and small scorpions. At least one species, the large slit-faced bat, even catches vertebrate prey, such as frogs and small birds.
The echolocation calls of slit-faced bats are relatively quiet and short in duration, and they seem to target their prey by hearing the sounds it produces, rather than by sonar. They give birth once or twice each year.