Okay, so I'm thinking ahead to spring. Living here in PA in the winter, one has to do something. Anyway, I'm wondering if anyone out there has any ideas on how to "kitty-proof" my windows. After being flooded this year, I'm definitely going to want to leave my windows open to circulate fresh air. The fear is...my screens aren't that sturdy. I'm especially concerned about the upper level windows where the pigeons like to roost. Are there any window guards out there that are small enough for cats that can allow fresh air in, yet still protect my girls if they decide they want to sit and enjoy the fresh air themselves?