Be kind to birds and small mammals with these Collar Bells. The RSPB have found that if you place one of these collar bells on your cat’s collar you cat will catch 41% fewer birds and 34% fewer mammals. This is because they are alerted to your cat’s presence sooner and have a better chance of escaping. The bells are simple to fit and prevent unnecessary slaughter. They also make a pleasant ringing sound and can let you know where your cat is which is always useful.