Under such conditions a farm flock is not often very productive, yet, as the birds secure a large part of their food by foraging, the flock may be more profitable than a more productive flock for which all food is bought and upon which a great deal of labor is expended. While this way of keeping fowls on farms is not in itself commendable, it is not to be altogether condemned, because circumstances often compel the farmer to treat his fowls as a sort of volunteer or self-producing crop. The conditions on a farm admit of this, and as a matter of fact the greater part of our enormous total production of eggs and poultry comes from the half-neglected flocks on the ordinary farms. Hence the conditions are tolerable where they are necessary, but whenever it is possible to give farm fowls enough attention to obviate the faults of common practice, the product and the profits can be greatly increased with very little increase in the cost of production. In this section we consider the best methods of securing this result when all the old stock is to be kept as one flock. Old stock and young ought always to be separated unless the old birds constitute an insignificant portion of the flock. [Illustration: Fig. 82. Good poultry house on Texas farm. (Photograph from Bureau of Animal Industry, United States Department of Agriculture)] =Single houses for farm flocks.= It is as true on a farm as elsewhere that the greatest yields of eggs and the best growth in young birds are secured when the flock is divided into small groups. But a farm flock of the class under consideration, while it makes its headquarters in such buildings as may be provided, will forage a considerable distance in every direction, going among growing crops from which the larger farm animals must be excluded, and also following the larger animals in their stables, yards, and pastures and picking up food left by them. As fowls also eat many weeds and seeds of weeds, and all kinds of destructive insects, the advantages of letting them run at large more than make up for lower production. Also the production is normal and can be easily maintained from year to year in the same line of stock, while high production secured by extra care is forced and can be maintained in the same line of stock for only a few generations. A flock of one hundred fowls or less, that run together, may all be kept in one house just as well as in several, if the size of the house and the equipment are in proportion to the size of the flock. [Illustration: Fig. 83. Rude poultry house on a Kansas farm. (Photograph from Bureau of Animal Industry, United States Department of Agriculture)]