Abstract: Spraying tubes (20 . . . ) through each of which a plurality of spraying holes are perforated along the longitudinal axis of each tube are placed in prescribed positions upper than feces boards (10 . . . ) of henhouses; and the spraying tubes (20 . . . ) are connected to agent-supplying means for supplying an agent such as a tank, a pump, etc. and airsupplying means for supplying compressed air such as a compressor, etc. The spraying holes make an angle not smaller than 5 degrees and not greater than 90 degrees as measured downward from the horizontal plane at the time of spraying an agent, in order to make it possible to spray the agent to feces boards (10 . . . ) and feces floor (12). The eggs of pests such as housefly and the like laid on the feces adhering to the feces boards and feces floor can efficiently and certainly be controlled.