Let’s look at the example of ant pheromone trails.
Ants searching for food
Ants search for food – but how do they find their way back to nest?
They lay down a chemical scent (pheromone) on the way out, during their search.
They follow this pheromone trail back to the nest.
But if one finds food, it will want to communicate this to other ants – how? – It lays down a stronger scent.
When other ants searching for food find such a trail they stop their own search, and follow the trail to the food. If an ant goes the wrong way, it will return to the nest. Arriving back at the nest, it turns round and follows the trail to the food. If there are many routes to the food, the shortest route will be used the most, and will have the strongest pheromone trail. So not only will the ant find food – it will do so via shortest route.