A method and apparatus for repelling insects with compound eyes employs diffraction gratings formed in movable structures, such as conventional compact discs (CDs), to create moving diffraction patterns of light from ambient light, or light from specially provided light sources, impinging on the gratings. The CDs may be suspended in a housing or frame that may be open at its sides or closed by transparent glass or plastic walls. For open sided housings the suspended CDs may be caused to turn or twist by ambient air currents or by a motor located in the housing and connected to rotate or turn the CDs. When the housing is fully closed, the motor drive effects movement of the CDs. The resulting moving light diffraction patterns repel insects having compound eyes.