Recall that when pedestrians enter an area in Amble, they have no knowledge of the layout; no map of walls or indication of best routes. They have to explore.

In this case, they enter the room and see two hallways roughly the same distance away. So some try one route, some the other. In addition, because they don't know which way leads to their destination, they will occasionally turn around to explore elsewhere. In all cases they are building and maintaining a decision tree which is dynamically modified as the environment is explored.