The bills of ducks are large, rather flat, and broad at the tip. The species to which most of our domestic ducks belong has no head ornaments corresponding to the comb and wattles of the fowl. There is one variety of this species which has a topknot, or crest. The Muscovy Duck, which is of a different species, has a bare face with a carunculated red skin. The plumage of ducks is very soft and dense, forming a thick covering which, when the feathers are in a natural position, is impenetrable to water and so perfect a protection from wind and cold that hardy ducks are quite indifferent to keen winds and low temperatures, and, if left to themselves, rarely seek shelter in winter. During a heavy snowfall they will get under cover to escape being buried in the snow. At other times they seem quite as comfortable on snow and ice as on the ground. One of the most interesting sights of the poultry yard is to see a duck sit down on the snow or ice when the temperature is below zero, draw up its feet and work them into the feathers at the side of its body until they are completely covered, tuck its bill into the feathers of its back until only the nostrils and a little of the base of the bill are exposed, and remain this way through the coldest nights rather than go a few feet to a comfortable house with warm bedding on the floor. Being better adapted to cold than fowls, they are, as would be expected, much more susceptible to heat and suffer greatly in hot summer weather if exposed to the sun or kept where there is not a good circulation of air. The tails of ducks are short, spread laterally, and are usually folded close and carried with the tip a little higher than the base. The legs are very short, comparatively slender, and weak. Most ducks walk awkwardly and fall down and flounder about helplessly when they try to run. The legs of a duck are so weak that it is not safe to catch or handle them by the legs, as fowls are usually caught and handled. It is very easy to break or dislocate the leg of a duck in this way. Hence, the usual method is to catch and carry them by the neck, which is very strong. Most persons who are not used to handling ducks are afraid of choking them by grasping the neck firmly, but there is very little danger of this. The feet of a duck are webbed between the forward toes, which makes them more serviceable as paddles in swimming. They are not suited to perching. There is a wild tree duck, and it is said that the domestic Muscovy Duck sometimes alights in trees or on objects above the ground, but the familiar kinds of ducks rest only on the surface of the land or on the water.