This paper deals with the problem of multi-robot border patrolling. The patrolling algorithm is designed by resorting to the behavioral control framework and is organized in a hierarchical structure. Several Elementary Behaviors are defined, which are the basis of the concept of Action, placed at a higher level of abstraction with respect to the behaviors. Each Action is obtained by properly combining multiple Elementary Behaviors via the Null-Space-Behavioral control framework. For the sake of robustness, the overall patrolling algorithm is fully decentralized, since explicit communication between robots is not needed. A a Fuzzy Inference System is designed to select the proper Action according to local sensor information only. The algorit...