Comparison of the number of escaped ants between treatment and control experiments using the t-test.

<p>One, two, and three stars indicate a <i>P</i>-value below 0.05, 0.01, and 0.001, respectively. (A), (B), (C), (D), (E), and (F) compare the results of the 1<i>w</i> (0.5 cm), 2<i>w</i> (1.0 cm), 3<i>w</i> (1.5 cm), 4<i>w</i> (2.0 cm), 5<i>w</i> (2.5 cm), and 6<i>w</i> (3.0 cm) exit widths, respectively. Many more ants escaped during the treatment experiments than during the control experiments.