Before revision:  The model yields, under certain assumptions on the parameters, that ants can successfully recruit others to food sources, and that a trail network pattern will emerge .
After revision:  The proposed tropotaxis model relating the pheromone field to the orientation changes is similar to Weber's law, but depends explicitly only on the gradient of the pheromone concentration. We identify ranges of values for the model parameters that yield the emergence of two key foraging patterns: successful recruitment to newly found sources, and that a trail network pattern will emerge .