A bee can find the Sun through cloud, by the polarisation of the sky

Sunlight scattered by air is polarised in a pattern that points back to the Sun. A bee can see that pattern, and can steer by it when the Sun itself is behind cloud, so long as some blue sky remains.

Karl von Frisch showed that honeybees dance the direction of food relative to the Sun, and then showed what happens when the Sun is hidden. If a patch of blue sky remains, the dance stays accurate. If that patch is covered, it degrades. A polarising filter over the patch twists the dance by the same angle. The bee is not guessing from brightness. She is reading the direction the light is vibrating. Ommatidia in the dorsal rim of the eye are built for that, with their analysers lined up. The pattern of polarisation in the sky is fixed to the Sun's position. Learn the pattern and you know where the Sun is without seeing it.

Complete grey overcast erases the cue, and then the bee leans on landmarks, or waits. The polarised sky is a backup for a broken view, not a supernatural sense. It is still a sense a human does not have. Two people can look at the same blue patch and not know, from the light itself, which way the Sun lies. The bee knows, and she can report it, in a dance, to a sister who has not been outside.