i would advise http://www.amazon.co.uk/Rentokil-LFC61-Ultra-Sonic-Repeller/dp/tech-data/B003ANX7M2/ref=de_a_smtd
they work pretty well with no harm to them.
....I've had one of those devices and it cost me nearly £50! It didn't do the job because it couldn't cover all the directions from which a cat can enter my garden. However, a neighbour's cat from across the road used to regularly ambush and kill birds in my garden and I made a note of his favourite ambush spots and set up the device accordingly. But it didn't make the cat even flinch, let alone go away. So I resorted to shouting and chasing.
Suddenly this cat stopped coming into my garden and I heard he had been hit by a car while crossing the road and recovered but lost his tail. I also learnt that the cat has been deaf for a very long time! Hence why my expensive device was useless. That cat never ventures across to my side of the road now.
I don't hate cats but I get a lot of wild birds in my garden and also have a wildlife pond. I don't mind the occasional visit from a Badger or Mole, or a raid by the local Sparrow Hawk which killed a Wood Pigeon last year but at least she ate it - I observed her for hours.
The cats were getting too regular but I think they are getting the hint that they are very unwelcome in my garden. A Super Soaker appeals the most to me and I can use it from indoors too.
I much prefer dogs to cats and friends with dogs are always welcome visitors.
^ Millie
