The Swiss Entomologist, Felix Santschi, is best remembered for his studies of ant navigation. In the deserts of Tunisia, ants are surrounded by sand that offers few landmarks for guidance. He hypothesized that the ants might use the sun for navigation.
Santschi observed a line of ants traveling back to the nest and placed a board such that it would block the sun from view. The ants became disoriented. Instead of continuing toward the nest, the ants moved back and forth as if they had lost their sense of direction. Santschi then placed a mirror directly opposite the sun. The ants were still not able to see the sun, but they were able to see its reflection in the mirror. The ants soon reoriented, but instead of returning toward the nest, they were now moving in the mirror opposite direction, away from the nest. Santschi concluded that desert ants were using the sun to navigate to their nest.