Cooperative transport by ants and robots

In several species of ants, workers cooperate to retrieve large prey. Usual ly, one ant finds a prey item, tries to move it, and when unsuccessful for some time, recruits nestmates through direct contact or chemical marking. W hen a group of ants tries to move large prey, the ants change position and alignment until the prey can be moved toward the nest. A robotic implementa tion of this phenomenon is described. Although the robotic system may not a ppear to be very efficient, it is an interesting example of decentralized p roblem-solving by a group of robots, and it provides the first formalized m odel of cooperative transport in ants. (C) 2000 Elsevier Science B.V. All r ights reserved.