Communication by tandem running in the ant Camponotus sericeus

1. Camponotus sericeus recruits nestmates to newly discovered food sources or nest sites by the tandem running technique. 2. The food alarm consists of short lasting fast runs inside the nest and brief food offerings. The "invitation behavior" for following to new nest sites is different: a recruiter faces a nestmate, grips it on the mandibles, pulls it forward and while turning around 180 °, loosens the grasp and presents the gaster. When the leader is then touched at the gaster or hindlegs by the follower, tandem running starts. 3. Dummy experiments have shown that these tactile stimuli are important to release leadership behavior during tandem running. Furthermore we demonstrated that the follower ant is bound to the leader by a surface pheromone. In addition a mechanical contact to the leader ensures a precise orientation during tandem following. 4. The leader ant discharges a trail pheromone out of the hindgut. It has been shown that these chemical trails are not important for recruitment in the tandem running technique. However, they are used as orientation cues.