The edges between the individual knots are chosen as heuristic values.
The Ant-Routing tables contain the marking strengths of the edges.
The History list contains knowledge. To go to every town only once every agent has a backup memory in which the attended cities are entered as a list. With this memory you can calculate the quality of the way.
An evaluation occurs after the end of all agent tours. Every agent then amplifies, depending on the quality of her tour solution, the density of pheromons on her way.