I am asked to describe how the theory of diffraction grating allows us to understand the extreme sharpness of irridescent colors seen coming from beetles, bird feathers, butterflies, etc. Then, explain if this occurs in all natural objects that being with the letter 'b.' I am not quite sure what the question as asking. I understand defraction but how could a feather, or a beetle defract light? When light bounces off of the beetle, is there a diffraction grating on the beatle that changes the light into different intensities when I look at it from variable angles? And what about all natural objects that being with the letter b?