Most people are not aware of it, but like many other animals our eyes are sensitive to polarisation. A bright, polarised scene brings about a butterfly-like yellow and blue structure called "Haidinger's brush". With some training, this brush can be used to determine polarisation.
Many underwater creatures, like squid and shrimp, have polarised vision. This allows them to spot other creatures that they consider lunch amongst the background light which is quite polarised. But some of these creatures have adapted to this strategy by manipulating the polarisation that they reflect themselves.
The dung beetle spends most of his time rolling around balls of... well... dung. These balls are so large that he cannot really see where he is going. Fortunately, he has polarised vision and he uses the sky polarisation to navigate. Amazingly, he doesn't only observe the blue sky during the day, but he can apply the same trick during the night when the moon is up.
Scarab beetles are circularly polarised because their shells are almost perfect circular polarisers. They make light circularly polarised even more efficiently than our current state-of-the-art human technology. We are therefore trying to artificially recreate the tiny structures of beetle shells to improve our own polarisation technology.