We have a small patch of soil (weeds) outside our front door. The patch in question is actually next door's and is where they keep their wheelie bins but the area closest to our front door is used regularly by a cat and/or a fox as a toilet. It utterly stinks. Every time we leave the house or come home. I've removed the shit everytime but they just come back and do it again. Have previously used sonic deterrent, citrus peel, coffee grounds - none really work. Has anybody ever laid down those spikey plastic mats you can get on amazon to make it uncomfortable for animals to sit while doing their business and has it worked? I don't know whose cat it might be.