I've long used solar-powered aliens in Traveller, but as it turns out, we don't need to travel to other stars to find critters fueled by the sun."The pigment melanin gives the [Oriental] hornet [(Vespa orientalis)] its dominant brown colour. The pigment xanthopterin, in the head and abdomen in a form of stripes and bands, gives the Oriental hornet its bright yellow colour," explains Dr Plotkin.
"Xanthopterin works as a light harvesting molecule transforming light into electrical energy."
. . .
"We assume that some of the energy is transformed in a photo-biochemical process which aids the hornets with their energy demanding digging activity," Dr Plotkin told the BBC. (source)
Nature is so bloody cool.