Fig. 3. Maze with covered middle segment and open bends. The Perspex did not cover the bends, allowing a view of the sky up to 15 cm into the middle segment on both sides. (A) Eastward orientation. Conventions as in Fig. 2: mean vectors 347.2°/351.1°/344.0°; at all radii not significantly different from 355° (open arrowhead), but highly significantly different from 315° (P<0.01); vector lengths 0.86/0.94/0.97; N=25, 25, 15. Note that in this maze a -5° or +5° deviation from a purely northern course is now expected, even if the ants had ignored the covered middle segment, since an uncovered middle segment of 30 cm has to be taken into account for the calculation of the expected home vector. (B) 26.4°/27.1°/36.8°; 0.95/0.96/0.98; N=21, 21, 12. At all radii mean vectors significantly different both from 5° (open arrowhead) and from 45° (P<0.01), except at 3 m radius (not significantly different from 45°). Mean vectors of A and B significantly different (Watson-Williams test with Bonferroni correction, P<0.01 to 0.001).