Scientists have been fascinated by the diamond weevil ever since it was discovered a century ago.
Now, using powerful electronic microscopes, researchers at Groningen University have discovered why it's so sparkly.
It's because tiny scales in the pits on the weevil's wing are the same shape as actual diamonds and reflect the light just like the real thing.
The team now hopes to find out why the beetle evolved this way.
Bodo Wilts, the scientist in charge of the research, said: "We are going on with the same weevil and looking for a biological function - I am sure there is one."