"Later Bermann says like the screeching of bats, quoting Herodotus."

The Garamantians have four-horse chariots, in which they chase the Troglodyte Ethiopians, who of all the nations whereof any account has reached our ears are by far the swiftest of foot. The Troglodytes feed on serpents, lizards, and other similar reptiles. Their language is unlike that of any other people; it sounds like the screeching of bats.

Herodotus, The Histories. Book 4. Translated by George Rawlinson.