If the uninvited animal in your back yard always get the fruit before you, hanging CDs on trees is a very easy and effective way to drive them away. It is humane, organic, and the old CDs will not end up in landfills. Use your old and unwanted CDs before you throw them away. But if you don't want to forego your CD collection, you can get cheap scrap CDs from a CD replication company in San Jose, CA and here is the link.