Why Do Ants Follow Ant Trails?
Most ordinary ants follow ant trails to and from food sources. Ants employ an odor language when gathering food. When an ant finds food, it hurries back to the nest, pausing along the way to mark the trail with bits of scent from its body. When the ant gets home, it lets other ants taste the food. The other ants then rush out and follow the odor trail to the food supply.
There are two antennae (feelers) on an ant’s head which are used for smelling, tasting and touching. When ants meet, they are likely to stop and share drops of food or touch antennae. The paired antennae provide information about the direction and intensity of scents. Since most ants live on the ground, they use the soil surface to leave pheromone trails that may be followed by other ants.
Ants use pheromones for more than just making trails. A crushed ant emits an alarm pheromone that sends nearby ants into attack frenzy and attracts more ants from farther away. Several ant species even use “propaganda pheromones” to confuse enemy ants and make them fight among themselves.
Pheromones also are exchanged, mixed with food, and passed by trophallaxis, transferring information within the colony. This allows other ants to detect what task group (e.g., foraging or nest maintenance) other colony members belong to. In ant species with queen castes, when the dominant queen stops producing a specific pheromone, workers begin to raise new queens in the colony.