Ducks, being aquatic birds, do not require heated apartments, nor roosts on which to perch during the night. They squat on the floors, which must be dry and warm. They should, if possible, be kept in a house separate from the other poultry, and it should have a brick floor, so that it can be easily washed. In winter the floor should be littered with a thin layer of straw, rushes, or fern leaves, fresh every day. The hatching-houses should be separated from the lodging apartments, and provided with boxes for the purpose of incubation and hatching. In its wild state the duck pairs with a single mate: the domestic duck has become polygamous, and five ducks may be allowed to one drake, but not more than two or three ducks should be given to one drake if eggs are required for setting. Ducks begin laying in January, and usually from that time only during the spring; but those hatched in March will often lay in the autumn, and continue for two or three months. They usually lay fifty or sixty eggs, and have been known to produce 250. The faculty of laying might be greatly developed, as it has been in some breeds of fowls; but they have been hitherto chiefly bred for their flesh. They require constant watching when beginning to lay, for they drop their eggs everywhere but in the nest made for them, but as they generally lay in the night, or early in the morning, when in perfect health, they should therefore be kept in every morning till they have laid. One of the surest signs of indisposition among them is irregularity in laying. "The eggs of the duck," says Mr. Dickson, "are readily known from those of the common fowl by their bluish colour and larger size, the shell being smoother, not so thick, and with much fewer pores. When boiled, the white is never curdy like that of a new-laid hen's egg, but transparent and glassy, while the yolk is much darker in colour. The flavour is by no means so delicate. For omelets, however, as well as for puddings and pastry, duck eggs are much better than hen's eggs, giving a finer colour and flavour, and requiring less butter; qualities so highly esteemed in Picardy, that the women will sometimes go ten or twelve miles for duck eggs to make their holiday cakes."