It's hard to get a cat with a sprayer as they are so quick and you won't get near enough, so you have to be sneaky. I have a cat, but I tell my neighbour to turn the hose on her if she's a problem. It won't hurt her, but will shock her enough to deter her. Or you could leave the sprinkler in the area where the cat goes, ready to turn on when it arrives. As a deterrent the RSPB recommends the ******** (www.conceptresearch.co.uk). No idea if it works, but I know the sillouettes don't as I have seen my cat walking past one. Hope that helps.