Ants can recognize and detect the location of chemicals (such as sugar and sweets). After an ant finds food, it turns around and finds a different pheromone trail back to the rest. While it travels home, it lays down more path back to the rest.
When other worker ants come across the pheromone trail, they cease their search for food, which is often already in progress, and they adhere to the pheromone trail, which comes directly from the food source. On the other hand, carpenter ants, which are sometimes called wood ants, use a combination of pheromones and visual memories to find food.
In a colony, worker ants are naturally saddled with the responsibility of getting foods for the rest of the colony. Whenever there's a need for them to look for food, the worker ants will move out of their nest in a bid to find what they will eat. Once they step out of their nest, each ant will release a substance known as pheromones on the ground. This is important so that they can easily find their way back to the nest should they find some food particles for the rest of the colony.
Although ants have two types of eyes, they don't usually have good vision with their eyes, so they rely mostly on their antennas to smell, communicate, and to respond to whatever they are commanded to do. The moment an ant locates any kind of food, it will smell the food using the antenna just to be sure if it is something they can eat. If the food location is spotted by a single ant, it will go back to the nest to inform others.