This paper proposes a mechanism for visually covering an area by means of a group of homogeneous reactive agents through a single-query roadmap called Weighted Multi-Agent RRT,
. While the agents do not know about the environment, the roadmap is locally available to them. In accordance with the swarm intelligence principles, the agents are simple autonomous entities, capable of interacting with the environment by obeying some explicit rules and performing the corresponding actions. The interaction between the agents is carried out through an indirect communication mechanism and leads to the emergence of complex behaviors such as multi-agent cooperation and coordination, path planning and environment exploration. This mechanism is reliable in the face of agent failures and can be effectively and easily employed in cluttered environments containing narrow passages. We have implemented and evaluated the algorithm in different domains and the experimental results confirm the performance and robustness of the system.