I don't know if there is much truth to this, but my mom told me that cats love to pee on dirty things so if the rugs were dirty that could be why. Also, to eliminate pet odors on something they peed on, I use a very strong spray cleaner called Awesome. It's available at most dollar stores, more specifically dollar tree always has it. I sprayed it on some things my cat peed on and he hasn't gone on them since.