Sawyer observed ants digging tunnels in his back yard and wondered what time of day the ants were most actively digging the tunnels. He decided to investigate whether ants dig longer tunnels in the light or in the dark. He thought that ants used the filtered light that penetrated the upper layers of soil and would dig more tunnels during the daytime hours. Ten ant colonies were set up in ant farms with the same number and species of ants per ant farm. The same amount of ant food was given to each colony, and the colonies were
kept at the same temperature. Five of the colonies were exposed to normal day light and five were covered with black construction paper and did not receive light. Every other day for three weeks, Sawyer measured the length of the tunnels in millimeters using a string and a ruler. Averages for the light and dark groups for each measured were calculated. The averages are listed in the following chart.