In general there are required three different brooder houses. The first of these requires sufficient heating capacity so that the temperature of the house itself can be maintained at 65 to 70 degrees even in the cold weather of winter or early spring. In addition, hovers are required in this house under which a temperature can be maintained from 80 to 90 degrees. For convenience this house will be spoken of as brooder house No. 1. A second brooder house which can be called brooder house No. 2 will be required which is equipped with heating apparatus so that the temperature can be run up to 60 degrees when required. The third brooder house known as brooder house No. 3 is a cold brooder house or one without artificial heat. It furnishes shelter for the young ducks where they can be driven in at night and during the day in cold weather. As the ducklings pass out of the brooder house No. 3 they are housed in sheds or shelters with yards which usually extend into the water but which may not do so in all cases. Brooder House No. 1 The length of this house determines its capacity, the required amount of which will depend upon the output of any particular plant. There should be brooder capacity in this house sufficient to care for approximately 1/4 of the total output for the year at one time. _Construction of House._ A suitable house which has been in practical use for some time consists of one 20 feet wide and running east and west with windows in the south or front side. If the location were right such a house could be run north and south to good advantage and should then have windows on each side so as to let in the sunlight from both directions. The front wall of this house is 7 feet high, the back wall 4 feet. The ridge of the house is about 2 feet in front of the center, the front slope of the roof having an eight inch pitch while the back slope has a 6 inch pitch. The roof rafters are 2 x 4's placed every two feet. The studs and plates are likewise 2 x 4. The walls are made of matched material. The roof is constructed of 1 x 2 inch strips placed every 4 inches and these covered with shingles. Tie beams every 8 feet extend from front to rear plates. This particular brooder house is not ceiled but a good tight ceiling 8 feet above the walk or runway would make it easier to keep the house clean and would also render it somewhat easier in cold weather to maintain the temperature desired. The house is built on a concrete wall or foundation and a dirt floor is used but the dirt must be filled in well above the level of the ground outside so that there is no danger of water coming into the house or the floors becoming damp or sloppy. Windows are placed in the front wall, one to each pen. In every other pen there is a small door in the back of the house to facilitate cleaning out the pens. A window can be substituted for this door to good advantage as it makes the house lighter.