level of path use, and avoided using completely unused paths. This is the opposite of what was predicted from the results of Czaczkes et al. (2013a). The results of experiment 2 demonstrate that the preference for used paths was dependent on a qualitative differ- ence in the number of perceived (dummy) ants. Under a quanti- tative difference, i.e. 10 versus 3 dummy ants, colonies' preference for the treatment path was weak or nonexistent. In experiment 1 colony-level path choice occurred very rapidly, within 3 min, and well before any reduction of pheromone deposition due to perceived path use could begin. This mirrors the path choice speed