Muller-Lyer illusion, which produces different subjective shaft length depending wing directions, is well known and studied in human subjects. To explain this illusion occurrence, the uncertainty principle is sometimes used and studied as model approaching. Here, we introduced arrow-shaped food to garden ant Lasius.niger colony and investigated similar illusion-figures could occur. Our results suggested that forager's interaction mapped to above principle and might be regarded as explaining of this illusion origin based on locality.