The expression is used to refer to someone who goes to bed very early. In fact, the life of chickens is closely related to light, which, depending on the context, can be that of the sun or artificial lamps. If raised in their natural environment, hens spend many hours outdoors, adapting their behavior to the rhythm of the seasons. Differently, hens in intensive battery and trellis farms are raised throughout the year according to an artificial lighting program, pre-established to control egg laying. In this case, the vital conditions are more monotonous than those of free-range breeding, which, on the other hand, is less profitable.