Can ants move from any point to any other point with the same cost?

Why in Case 1 there are non-visited points? Why did the ants stopped? Is this a random walk on a line?

In a travelling salesman problem there are costs to the connection of towns (points) - some connections are more difficult and costly than others. If you allow all points to be connected with each other and with same cost, then just list your points and move from the first to the last, one after the other.