Table 1.

Experimental paradigms

Experimental paradigm	Training (inside the channel)	Test (in the open)	Fig. no.
I	SUN plus SKY	SUN plus SKY	2
II/1	SUN	SUN plus SKY	3
II/2	SUN	SUN	3
III	SUN plus SKY	SKY	4
IV	SUN plus SKY	1 and 2, SUN	5 and 6

In experimental paradigm IV, tests 1 and 2 differed in the way that the ant’s polarization compass was excluded experimentally. In IV/1, the compass was excluded by occluding the dorsal rim areas of both eyes (and the ocelli); in IV/2, the compass was excluded by optically cutting out the UV range of the spectrum. SUN, direct sunlight; SKY, polarized skylight.