An ANT is a mobile agent that is capable of solving various kinds of routing and congestion problems in computer networking by continuously modifying routing tables in response to congestion. In a distributed problem solving paradigm, a society of ANTs (each contributing some information) collaborate to solve a larger problem. In recent years, ant-based algorithms were used to solve classical routing problems such as: traveling salesman problem, vehicle routing problem, quadratic assignment problem, connection-oriented/connectionless routing, sequential ordering, graph coloring and shortest common supersequence. This paper introduces the general idea of Ant-based algorithms with a focus on ant colony optimization (ACO), and their features, strengths, weaknesses and applications in network routing. The contribution of this paper is the proposal of a multiple ant-colony optimization (MACO) approach for network routing.