Squirrels can be a nuisance to many homeowners, invading attics and chewing through wiring, or feasting on bird seed or landscaping plants. Many commercial squirrel repellents contain familiar ingredients that work to deter squirrels from a home or garden. Some people prefer to make homemade squirrel repellent using similar ingredients.
Ammonia has a strong odour that can deter squirrels and other animals. Some commercial squirrel repellents contain small amounts of ammonia. Colorado's Evergreen Animal Protective League (EAPL) suggests soaking rags in ammonia and placing them in areas where squirrels are unwanted. Ammonia-soaked rags work best in places like attics, where the smell won't disturb humans. Ammonia should be kept out of reach of children.
Hot peppers are another ingredient in commercial squirrel repellents. The capsicum in peppers irritates squirrels, thus deterring them from an area. To keep squirrels away from outdoor plants, exterminator Rick Steinau suggests mixing a small bottle of hot sauce with a gallon of water and a teaspoon of dish soap and spraying the solution on plants. The solution will need to be reapplied after rain or watering.
Bird lovers can use hot peppers to keep squirrels out of bird feeders. While eating hot peppers is uncomfortable for squirrels, birds are not affected by capsicum. The makers of Hare-Less animal repellent claim their hot pepper spray can be sprayed directly on bird feeders and bird seed to deter squirrels without causing harm to birds.
Some gardeners use squirrel repellents that contain the oils of many different plants that are believed to deter squirrels. These oils provide a natural alternative to harsher repellents. Garden Naturals makes a squirrel repellent spray that combines hot pepper sauce with oils from garlic, onions, parsley, basil, thyme, coriander, cumin, mustard, rosemary, oranges and lemons. The company claims this mix of oils repels not just squirrels, but also deer, rabbits and plant-destroying insects.
Some homeowners have success deterring squirrels using mothballs. The EAPL suggests filling a sock with mothballs and placing it in the area where squirrels are becoming destructive. Mothballs contain chemical pesticides and are harmful to children, birds and household pets if ingested. It's best to use mothballs in areas that are completely inaccessible to small children and animals.
Various commercial squirrel repellents use dried or liquid urine from natural squirrel predators, most often coyotes, to frighten squirrels. The squirrels smell the urine, think a predator is near, and leave. Animal urine is safe to use around children and pets. Many gardening shops and nurseries sell concentrated predator urine.