How can I stop my cats from doing this? They wear quick release collars with bells already and are kept in from around 6 PM until it's light in the morning, around 7.30 AM. I had a dead mouse last night and a live one tonight which I spent an hour trying to catch. We've also had other mice, frogs and a slow worm in the last couple of months. I don't want to keep coming home to the bodies. Are my only options to lock them out all day or shut them in all day?