The noxious odor of cat urine spray left by a neighborhood cat on the outside of your house can drive you crazy, but this kitty doesn't mean any harm. The stray feline is simply marking his territory, which may unfortunately include your yard, porch or even your front door. To stop the cat from spraying your house, you'll need to use harmless deterrents to discourage him from returning.
To prevent a stray cat from coming into your yard, porch or near your front door, install an ultrasonic motion-activated cat deterrent in that area. These devices are battery operated. When a cat comes near the device, it lets out a loud sound at a very high frequency. While you won't hear the noise, the offending kitty will and it will discourage him from returning. In garden areas like your front or backyard, try installing a motion-activated sprinkler. When the cat comes close to the sprinkler, he will be sprayed by a harmless spritz of water.
Cat Deterrent Scents
Generally, cats don't like strong citrus odors. Place orange peels around your yard to deter cats from coming near your home. Spray your porch and door with a commercial cat repellent that contains a citrus oil. The scent will smell pleasant to you but unpleasant to the cat. Other essential oils, like eucalyptus, citronella and lavender also deter cats. Mix about 15 drops of them with a cup of water and spray it around your home every few days, especially in areas where a cat has sprayed before.
Unpleasant Surfaces to Deter Cats
Cats don't like the feel of rough or bumpy surfaces beneath their paws and will avoid areas with these unpleasant surfaces. Place upside-down plastic carpet runners in front of your door, your porch or in your garden to discourage stray cats from walking over and spraying there. Other surfaces like chicken wire, placed flat on the ground, will deter cats from walking over it in areas previously sprayed.
Physical Barriers and Cleanup
Place physical barriers in front of areas stray cats have been spraying. Screen in your porch or install a screen door in front of your front door. Place fencing around your home to help deter stray cats from wandering into your yard.
Thoroughly clean away any previous cat spray from your walls using an enzymatic cleaner or vinegar to eliminate the scent. The scent of cat spray tends to attract other cats back to the area to mark it again. Avoid using cleaners containing ammonia, which mimics the scent of urine and could attract the cats to the spot to mark.
Keeping Food Away and Other Options
If any of your indoor cats or dogs go outside, don't feed them there. The food may attract stray cats who will spray your home.
Contact an animal welfare group like Alley Cat Allies, which advocates for programs like trap-neuter-return. These groups will trap your neighborhood strays, have the cats spayed or neutered and return them to your neighborhood unharmed. Neutered cats are less likely to spray than those who are intact.