While pheromones explain the pharaoh ant's foraging ability, each forager's capability to find its way back to the nest requires a different explanation. In fact, the pharaoh ant relies on geometry to show it the way home. Each fork in the trail system spreads at an angle between 50 and 60 degrees. When returning to the nest, a forager that encounters a fork will almost always take the path that deviates less from its current direction. In other words, it will never choose an acute angle that would drastically change its direction. Using this algorithm, each forager is able to find its way back to the nest. If the fork angle is experimentally increased to an angle between 60 and 120 degrees, "M. pharaonis" foragers were significantly less able to find their nest. This method of decision-making reduces the wasted energy that would result from traveling in the wrong direction and contributes to the pharaoh ant's efficiency in foraging.