depending where they are scratching, you can put some tinfoil or bubble wrap where they are scratching as they dont like the sound. also we are having a prob at the moment where a couple of our cats keep jumping at the bird cage so we bought a sound thing that stops them going near the cage. you are supossed to use it near bird tables outside, but we use it indoors and it works. when they go near the area it sets off a sound that stops them going near it, and its not cruel.