To deeply exploit the mechanisms of ant colony optimization (ACO) applied to develop routing in mobile ad hoe networks (MANETS),some existing representative ant colony routing protocols were analyzed and compared.The analysis results show that every routing protocol has its own characteristics and competitive environment.No routing protocol is better than others in all aspects.Therefore,based on no free lunch theory,ant routing protocols were decomposed into three key components:route discovery,route maintenance (including route refreshing and route failure handling) and data forwarding.Moreover,component based ant routing protocol (CBAR) was proposed.For purpose of analysis,it only maintained basic ant routing process,and it was simple and efficient with a low overhead.Subsequently,different mechanisms used in every component and their effect on performance were analyzed and tested by simulations.Finally,future research strategies and trends were also summarized.