We have two 9 yr old, neutered outside cats that we resqued from an abandoned house when they were about a year old. We live in the country - they hunt on the property, don't roam far, and are well fed. One of them scratches on the screens outside our kitchen window - he first began doing this whenever it was time to eat (obviously he was telling us he was hungry). But it seems that more & more he does it at random times. He has never come in the house, so I don't think that's what he wants. Also, he is the shyer of the two, and it's only been in the last year or so that he's even let us get very near to him (they were both obviously abused as kittens and it took a long time for them to stop running from us whenever we would go outside). He's already ruined one set of screens which I just had replaced - now he's started on these. Does anyone know of anything that I could put on the screens, or on the sidewalk under the screens, to deter this cat, and that will last more than a few minutes?