They don't know exactly how the Oriental hornet's exoskeleton generates solar electricity, and they also don't know why. But icthyologists have confirmed that, somehow, the mix of pigments in the exoskeleton takes in sunlight and puts out electricity. It's not an efficient process, but no one knows why it exists at all. Did the hornet evolve this ability so it could carry an iPod? That makes as much sense as anything.