My cat's litterbox trained. But recently decided to use a vacant room (remodeling) to poop in. Still peeing in litterbox, but don't know why he's choosing to do this. Thought it might be territorial, as that's the room family/friends dogs stay in when here, but he started after new carpet was put in, and I thought territory marking was more pee. But only along a back wall in this room. Seems more behavioral but I have no idea what he's trying to do/tell me.