QUOTE (HamburgChris @ Feb 14 2006, 05:14 PM)

Maybe we will buy the ultrasonic thing!
Don't do it! I used to have a cat problem in my garden back in the uk - they just loved crapping in my flowerbeds & it stank, so one by one I tried all the options. First was the cat pellets, where the smell was meant to be too mild for humans, but would keep cats out of the garden. It worked fine until it rained, then all the smell was released at once & you couldn't breath outside, & the people next door complained their kid was feeling sick.
Next I tried the sonic IR trap - where if anything triggered the IR sensor, a 'Silent to humans' alarm would go off. Silent my arse - it was a high pitched scream which could be heard from anywhere in the house & gave you a headache in seconds. Didn't seem to bother the cats much, who kept up their nightly visits, but I could hear dogs barking for miles when it went off- so I got rid of that before anyone blamed me for their dog going mad & eating their kids.
Scaring the cats away with a BB machine gun didn't help much either - they just learned quickly not to come into the garden when people were around or they would be met with a hail of small plastic yellow balls (before anyone complains of the cruelty, I know it was the shock & not pain that drove them away, as one fat old tabby used to completely ignore it - you could just see him thinking 'What's this pratt up to now?' as the balls bounced off him). Gave up on that idea too when I got sick of collecting thousands of little yellow balls from everywhere.
Finally I heard a great idea from a mate - but sadly never got to put it to the test as I moved. I have read up on it since & it is meant to work, but its not easy. First you need to go to your local zoo, and buy some lion crap. Yes, I'm serious, and some zoo's do sell it just for this reason. You then fertilise your flower beds with it, & you will never see a cat near your garden again. It doesn't smell as bad as cat crap and after a day or 2 the smell is to faint, but should be effective for about 6 months.
If you try it, let me know if it works!