Later man invented new and improved methods of hunting. They also discovered fire and agriculture. They began to build huts and moved out of caves and valleys and tree shelters. They began to find means of protection against wild animals.
Still later, early men started domesticating certain animals for carrying loads. With the discovery of wheel, the means of transport were revolutionized. Man’s implements, tools and weapons also changed from clay, stone, wood to copper and then iron. Civilization kept progressing till it reached the modern level.