Pepper is a cruel 'deterrent' for unneighborly cats - SFGate
It is useless to speak of a single deterrent for cats, as what is efficient in one case can be the least efficient in tens of others.
@kindoak: Thank you. I think cats don't like the citrus smell because they have a much stronger sense of smell than humans. For whatever reason, it's a good deterrent from keeping a cat away from a certain area.
I have had cats for years and never had a problem. If you feel concerned, do not use it. I recommend it as an alternative to costly chemical based urine cleaners or cat deterrents.
The Scatmat is the perfect household deterrent for cats (and dogs)
Cat Repellents & Deterrents for Indoor & Outdoor | PetSmart
Deterring cats need not be expensive. There are plenty of do-it-yourself home remedies you can tryout - and now there is even a special plant for your garden or yard that will repel cats effectively. Once a cat is in your yard, one strategy is is toset about sowing some doubt in the cat's mind. An old gamekeepers trick is to create some flickeringrandom light reflections as a deterrent. For example you could place some plastic bottles half filledwith water in your borders. The cat sees the distorted reflections, gets spooked, and hopefully slinksaway. Perhaps even more effective (but maybe a bit unsightly) is to string some unwanted CD's togetherwith knots in between to keep them apart. These high tech cat distracters can then be hung across flowerbeds and vegetable plots or hung from trees. (My research shows that cats are most likely to be repelledby old ZZ Top CD 's...). Deterring cats need not be expensive. There are plenty of do-it-yourself home remedies you can tryout - and now there is even a special plant for your garden or yard that will repel cats effectively. Lean how to condition cats stay away without using harmful chemicals, poison and traps. Find more information on electronic, automated and motion-activated solutions. Take steps to select your cat deterrent and make your lawn, yard and garden unappealing to cats.I've tried some of the cat deterrent sprays and found them to be effective if you use them like they say to, i.e. once a day. I had a problem with my cats pulling up the carpet in the doorways to both of the bedrooms in my apartment. I started spraying the carpet every morning with that stuff (sorry, I don't remember the brand) for a couple of months, and it hasn't been a problem for almost a year.When the unit detects movement it automatically sprays a jet of water for a few seconds in a small arc. The sound and the water act as a double deterrent to cats and other animals who immediately run off and remember not to come back again.