What Can We Do About Cats?

Now, I have never been a cat lover. Some people are and some people aren't, all a matter of opinion. Cats have never really bothered me before but lately they are playing a bigger part in my life. Why you may ask? Well simply because over the last few months we seem to be having many visitations to our garden by them. They are digging in the soil and messing all over the place. This is definitely not nice. I have had to chase several off when they have been hunting the birds in the garden and so far have stopped them in their murderous intent. So what can I do about them?

As I say I am not a cat lover but I do not want to do them any harm, so how can I rid myself of this problem? I have tried some of the stuff that you buy in the shops to keep them away but it doesn't seem to work. I don't suppose that approaching the "owners" is going to do any good as there is not much they can do to stop them entering other peoples property and they have no control over them.

Any ideas anybody may have would be gratefully received. Starting to get towards the end of my tether!!!