
I'd like to see them try to poo on THIS!!! Yes, this is pretty much EVERY possible cat deterrent you can think of with the main feature of plastic forks, buried in the ground - prongs up! (this is where they - the evil neighbours' cats - seem to favour pooping in particular), sprinkled with crushed egg shells, littered with orange peel and liberally covered with ground black pepper - so far, so good.
...And yes, I HAVE considered sharpening each prong individually and dipping them in vinegar....!