Cat Claw Is Simply the Best Pigeon and Bird Control System in the World! Put the birds on the wing again ... instead of roosting on your building. Called Cat Claw, this product presents an inhospitable environment to birds, and interferes with basic biological needs for food and cover. By encouraging birds to move elsewhere, Cat Claw should prevent unsightly staining on building facades, eliminate unhealthy conditions in and around roof-top air conditioning and ventilating equipment and remove other distasteful annoyances associated with roosting birds--permanently.