Scientists already knew that the hornet species, for unknown reasons, produced electricity inside its exoskeleton, according to study leader Marian Plotkin of Tel-Aviv University.
Plotkin's late mentor Jacob Ishay made the discovery after observing that theinsect is active when the sun is most intense—unusual for hornets.
Plotkin and colleagues recently went a step further by examining the structure of the hornet's exoskeleton to find out how the electricity is produced.
Their research revealed that pigments in the hornet's yellow tissues trap light, while its brown tissues generate electricity. Exactly how the hornets use this electricity is still not entirely understood, Plotkin noted.
While solar cells using human-made substances are usually 10 to 11 percent efficient at generating electricity, the hornet's cells are only 0.335 percent efficient. For instance, the hornet still gets the vast majority of its energy from food.
But that's hardly the point, Plotkin said.
"We've seen solar harvesting in plants and bacteria, but never before in animals."
The brown tissues "are a lot like a light trap—only one percent of the light that strikes is reflected away," said Plotkin, whose study appeared in the December issue of the journal Naturwissenschaften.