Hello, I am new to this site & could really use some help. I have a neutered male cat who is always indoors. Lately, there have been some wandering tom cats outside. One (or perhaps more than one) has taken to spraying against a basement window located under my deck. The window is so poorly sealed that the urine spray is actually seeping through the window and onto the cinderblock in the basement. The basement then smells awful. I'm cleaning it as best as possible (a non-ammonia product), airing it out, and I'm not allowing my own cat to go downstairs. I haven't actually seen the cat who is doing the spraying, but we have saw cat paw prints in the snow that went under the deck. I know I can't stop an outdoor cat who isn't mine from spraying but I am really unhappy with this situation. Does anyone have suggestions about how I can block this cat from the window area? I don't want to have to put some kind of fencing around the entire bottom of the deck because it will cost a lot. Thank you for your ideas.