All birds are subject to deformities of the beak, which sometimes occur in freedom, but are usually due to the influences of captivity. The parrot's beak is often immoderately long, too much bent, or otherwise misshapen. In most cases such an abnormality is treated lightly, although it usually causes the loss of the bird. If the upper beak grows so far down over the under as to be a hindrance to picking up food, it must be cut back to its natural length, and this is best done by a skilled hand with a sharp knife. It can certainly be done more easily with sharp pincers, but this is more dangerous, as the sensitive, i.e., the fleshy part of the beak, may be thus injured. In any case, care must be taken not to break it off or tear into it, so that splits come in the horn which leads down to the pith, for then it is scarcely possible to heal them; they break open again and again, cause the bird much pain, and prevent it eating, so that it may probably die. Therefore, before being cut, the beak should be rubbed several times with warm oil. A split in the horn should be cleaned once a day with a brush, and smeared with a warm oily mixture. A beak which has been injured, and sometimes even a beak which has hitherto been quite sound, often begins all at once to increase enormously in size, growing an unnatural length, and the point at the same time splitting up in threads. Cause: Scanty or improper nourishment of the horny substance, and at the same time some particular irritation. Such a beak may be cut back with a pair of scissors, yet the bird is often lost from it, because the horn of the beak then begins indeed to grow fast, at the same time becoming soft, and either breaks off in little pieces, or bends, and is useless for cracking hard grains. Treatment: Natural food, especially give lime and sand; avoid mashy food and tit bits, and take the bird into the open air until the weather becomes cold.