How do ants find food and find their way home?

When a foraging ant finds food, it returns to the nest while dabbing pheromone from glands on its body onto the ground. Other ants detect this scent with their antennae and follow the trail, adding more pheromone if they also find food, so good routes become stronger. As food runs out, ants stop reinforcing the trail and the scent evaporates, sending foragers elsewhere. Shorter routes tend to win because ants complete them faster and lay pheromone more often. Desert ants, where scent trails do not last, instead navigate by the Sun’s position, polarised light patterns and by counting their steps.