Constant warfare with the colonies and the Kentucky and Virginia hunting shirt men had greatly reduced their numbers, but above all the terrible ravages of smallpox, the insidious effects flowing from the use of intoxicants, and the spread of venereal disorders among them, which latter diseases they had no means of combating, had carried away thousands and reduced the ranks of their valiant armies. Woe to the general, however, who lightly estimated their fighting qualities, or thought that these "rude and undisciplined" savages, as they were sometimes called, could be met and overpowered by the tactics of the armies of Europe or America! They were, says Harrison, "a body of the finest light troops in the world," and this opinion is corroborated by Theodore Roosevelt, who had some first hand knowledge of Indian fighters. The Wyandots and Miamis, especially, as well as other western bands, taught the males of their tribes the arts of war from their earliest youth. When old enough to bear arms, they were disciplined to act in concert, to obey punctually all commands of their war chiefs, and cheerfully unite to put them into immediate execution. Each warrior was taught to observe carefully the motion of his right hand companion, so as to communicate any sudden movement or command from the right to the left, Thus advancing in perfect accord, they could march stealthily and abreast through the thick woods and underbrush, in scattered order, without losing the conformation of their ranks or creating disorder. These maneuvers could be executed slowly or as fast as the warriors could run. They were also disciplined to form a circle, a semi-circle or a hollow square. They used the circle to surround their enemies, the semi-circle if the enemy had a stream on one side or in the rear, and the hollow square in case of sudden attack, when they were in danger of being surrounded. By forming a square and taking to trees, they put their faces to the enemy in every direction and lessened the danger of being shot from behind objects on either side.