We've been using 'silent roar' for several years, and until recently it was very effective. A few months ago we had new neighbours whose cats seemed to be impervious to the smell, so we've installed the ultrasonic devices front and back. They've taken a few weeks to be effective, but have worked a treat. Occasionally in the night we hear a yowling when a cat has been using our garden as a toilet, but obviously finds the ultrasonic sound distressing! I did notice that 'silent roar' says 'new improved' on the packet, so perhaps tha's the reason for it's decreased efficiency. Who knows?

I had been fighting a losing battle with cats for years but found that a combination of Silent Roar and the ultrasonic devices were the most effective so I hope they haven't changed the formula.

I found these other ideas of cat deterrents: [link] and [link]

I've got CATWatch which is the only one the RSPB approve of.

Try 2 litre pop bottles filled with water, the reflection of that cat frightens them off(so I am told)

That sounds interesting..have you heard if that works CaptainJon?

I haven't used anything yet but I'm getting annoyed with the cats in my Garden, most of my friends use the ultrasonic deterrents and say they work very well.

Although 55 pounds on the website YourfiveADay suggested seems rather steep.

I have just seen on another forum that the Catwatch is the only product tested by the RSPB and that the research was funded by the manufacturer. My search will continue!

As an update to my note of 22nd June, we've now a problem with the neighbour's cat every time my husband mows the lawn, as it always leaves a dollop afterwards, inspite of the ultrasonic devices. In the past we've tried the 2 litre bottles, but they had no effect whatever, and we're never around to spray the little blighters with water. That's why we were so pleased to discover Silent Roar, which worked for several years until recently.

I had a real problem with cats in the garden, they were digging up seedlings, pooing on the lawn, and leaving lovely presents of young dead birds
I asked around and one of my neighbours has a cat repeller - it sends out a high pitched noise when the cats walk past. Apparently he's had it for a couple of months now and no cats (including the rather persistant tabby that likes to frequent my garden!) - sounds like the perfect answer! I've ordered one just now, thought it might be useful to post on here. [link]