A group of five individuals moves from a collective slumber movement. This sample of the species appears to establish a behavioral sensitive transmission, resulting in mimetic and repetitive gestures. The emitted sounds could be artificially transposed into audible frequencies. Five people wear eye masks, masks usually used in planes to sleep. This small group is mu of a collective slumber movement. A kind of communication is established between them, a mimetic and repetitive gestures. The image was returned to the assembly. The soundtrack was composed from recordings of sounds emitted by bats. Initially, the ultra-sounds produced by bats are inaudible to humans. They were artificially transposed into audible frequencies.