Urine

• Some cat repellents are made of coyote or fox urine. Coyotes and foxes are feline predators, so cats will attempt to avoid areas where they may be in danger.
  
  

Plants

• Commercial cat repellents can use a variety of plants, or their oils, in ingredient lists. Some products use d-limonene, a citrus extract, while others may use allyl isothiocyanate, the essential oil of mustard or capsaicin, the compound that makes chili peppers hot. The essential oils of lemon grass, citronella and bergamot can be found on ingredient lists.
  
  

Considerations

• Use cat repellents in conjunction with other deterrents. You will need to reapply deterrents every few days and more often if it rains. Follow the directions on the container when you apply the deterrents.