Animals of suitable age, size, and conformation will ordinarily give little trouble and with systematic training and kind treatment will soon develop into excellent pack animals. Horses are usually preferable for use as pack animals which are led in accompanying commands mounted on horses, as they lead more freely than mules and their gaits conform better to those of the horses of the command. When not led and when worked in large numbers mules are usually preferable as they are more easily managed than horses under these conditions and superior as weight carriers.