Large numbers of the bat, Nycteris hispida, Schreber, have been observed at dusk flying out of the residual forest islands at Gadau. Some have been captured and placed in a large cage containing Glossina morsitans and G. tachinoides. The sleeping bats, hanging head downwards, are perfect complacent hosts; both species of tsetse have been seen to attack and feed on them on many occasions, and to experience no difficulty in becoming fully gorged.