I know this image is very silly and immature. But I couldn't find a good one. Okay. Let's dive in.
Ants leave pheromone trails as they move, which act as chemical signals for other ants. These trails help guide them along the path and serve as a communication method. Pheromones are chemical substances produced and released by animals, including insects, mammals, and even humans, to communicate with others of the same species. Each colony has a unique set of pheromones and they are highly volatile, meaning they can evaporate easily. So every ant leave pheromones as they move. By following the scent left by the leading ant, subsequent ants can maintain a straight path.
Ants have sensitive antennae that they use to feel their surroundings. If an ant encounters an obstacle or deviates from the straight path, it can sense it with its antennae and make adjustments to its direction, helping it stay on track. Some ants have a built-in sense of direction. They can use the position of the sun or landmarks in their environment to guide their movements. By keeping a reference point in mind, such as the sun, they can walk in a straight line.
These simple mechanisms help ants navigate and maintain straight paths.