Humane, effective, maintenance-free electronic bird repeller. Ideal to keep birds away from your property without messy or expensive chemical solutions. Features ultrasonic sounds that discourage birds but are silent to most humans. Repels pigeons, woodpeckers, swallows, starlings, sparrows, and other creatures. Coverage: Up to 900 square feet. Use on balconies, decks, yards, lawns, gardens, porches, buildings, greenhouses, and more. AC adapter included with 30-foot extension cord, or may be operated with (4) C batteries in motion sensor mode.