Sonic cat scarers

I had one of those electronic cat scarers and it was totally useless, I think the cats round here must be deaf.
One day I caught a cat spraying it and looking at me with disdain, that was the final straw.
I had all the fencing removed and solid metal fencing installed, cats can not get a claw hold so can not climb the fence, not one cat defiles the garden now.

Iv`e heard they work but only new cats visiting the garden.
Similar to devises tokeep mice out as i had some uninvited blightres a few months ago.
It did stop more mice coming in but those that were here were not detered.
Happily we did get rid of those guests.

Yes we have one in front and back gardens - bought from Amazon. They are very good as long as you make sure the battery hasn't run out. However it wasn't enough to deter the large rat that shinned up our bird feeder and feasted on the fat balls yesterday. Sadly the bird feeder is no more.

I bought a sonic cat scarer online last Autumn for £19.99 as I had fine slate chippings laid instead of a tiny lawn which was full of moss (no sun) and it was impossible to pick up the mess. Since using it I've had no bother, I know it's working because children and teenagers look to see the source of the noise that they hear when they pass my house.
I found the best way to clear the mess was to douse it in Jeyes fluid and then pour boiling water on it.

I had one, it was connected to an electricity supply. I am not sure they work. Thin short sticks in the ground worked well as did wire mesh just under the soil. I even tried lion wee pellets but the best things to work were moth balls from ebay. The smell put them off