Cooperative transport by ants and robots

In several species of ants, workers cooperate to retrieve large prey. Usually, one ant finds a prey item, tries to move it, and when unsuccessful for some time, recruits nestmates through direct contact or chemical marking. When 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 implementation of this phenomenon is described. Although the robotic system may not appear to be very efficient, it is an interesting example of decentralized problem-solving by a group of robots, and it provides the first formalized model of cooperative transport in ants. (C) 2000 Elsevier Science B.V. All rights reserved.