All supposed exterior signs of danger that a bull gives, such as pawing the ground, threatening with his horns, or bellowing are forms of bluffing. They are warnings given in order that combat may be avoided if possible. The truly brave bull gives no warning before he charges except the fixing of his eye on the enemy, the raising of the crest of muscle in his neck, the twitching of an ear, and, as he charges, the lifting of his tail.