The other ants will now be attracted to the shorter, more efficient path because of its concentration of pheromone. Individually, these ants have little intelligence. They don’t have managers or any supervision. Yet, collectively they create a thriving community.
Biologists explain the way social insects do this. If two ants would leave the nest at the same time and follow different routes to a new food source, they mark their exploration trail with pheromone. The ant that found the shorter route will return first. What happens is that this route will now be marked with twice as much pheromone as the other path taken by the second ant, who hasn’t yet returned.