Here's a way to gain some "sustainability points" from your customers while deterring pest birds. These solar powered bird control devices keep seagulls, pigeons, and crows, from landing by whisking them away with large rotating "arms" that cover up to five feet in diameter. The arms turn continuously at 30 RPM.The heavy duty, brushless motor is powered by sunlight during the day and stored energy at night. Solar Bird Repellers can be placed wherever they're needed to deter flocks of pest birds.