That's very unusual for a cat to choose to poo on a lawn so frequently - after years of keeping and watching cats, I observed they only ever poo on the grass if its been left uncut for a while and is eiher long or a bit shaggy,, or its an un-neutered tomcat - they don't obey the usual rules of scratch, poo, bury and just do what they like when they like. Just wondering if its another animal like a fox or something...

You can get a motion sensor which either causes a blast of air or water to frighten off cats. The downside is, you might frighten off visitors as well!

Agree with Cammomile - the most effective is a motion sensor attached to water, like a sprinkler. Everything else stops working when it rains and needs regular replenishment.

These kinds of cats normally have a very short life so you won't be bothered for long.

I think you can get motion sensors that emit supersonic sounds that only annoy the animals not people.The dog could well make a worse mess by weeing on the grass if you don't watch it! (Its being so cheerful that keeps me going...)

I don’t think it’s a fox as it doesn’t smell like one and I know that smell exactly as one dog we had loved to roll in it! It’s too small a load for anything bigger. The grass is scratched up too - a moss scarifier! Someone in the U3A gardening club said very hot curry powder works well but the sensor doesn’t. I’m wondering what the curry would do to the lawn though. Not that the lawn is in a great condition but I wouldn’t want to make it worse. I appreciate all the suggestions, thank you.

Very hot curry powder contains chili, which is not recommended by the RSPCA - whilst we may not like these constant visits, chili powder can cause a great deal of pain to a cat or other animal, including dogs, especially if it ends up in their eyes. Black pepper is a slightly less harmful deterrent.

The only sensor system that works is one attached to a sprinkler, in my experience, and it doesn't sound like a practical solution for your situation.

I tried chilli powder to discourage a badger and a bank vole that was removing the bark from a shrub, but then i got a bit in my eye and have never used it since although it did discourage them. I was very repentant about ever having used it, and now I have a bagful I don't ever expect to need for anything!