Ant robotics is a special case of swarm robots. Swarm robots are simple (and hopefully, therefore cheap) robots with limited sensing and computational capabilities. This makes it possible to deploy teams of swarm robots and take advantage of the resulting fault tolerance and parallelism. Swarm robots cannot use conventional planning methods due to their limited sensing and computational capabilities. Thus, their behavior is often driven by local interactions. Ant robots are swarm robots that can communicate via markings, similar to ants that lay and follow pheromone trails. Some ant robots use long-lasting trails (either regular trails of a chemical substance or smart trails of transceivers). Others use short-lasting trails including heat and alcohol. Others even use virtual trails.