#3: "Presents" on your lawn from neighboring animals
"I had problems with some of the dogs in my neighborhood, and I gave up trying to train the neighbors," Green says about pet owners who don't pick up after their dogs on long walks. If you're a pet owner, remember to bring plastic baggies with you so as not to offend homeowners along your walk. But if you're said homeowner, Green suggests sprinkling cayenne pepper on the spot that dogs favor.
"Dogs generally stick to the same spot [on a lawn] for doing their business," he says. "They're looking for that scent, so when they smell cayenne pepper, they don't like it, and they'll go somewhere else." This deterrent takes a few weeks to be effective, he says -- you need to sprinkle the spot with pepper every day -- but once it starts to work, you won't have any more problems. The same trick works for keeping pets out of your flower and vegetable gardens: Mix two ounces of cayenne pepper with three ounces of mustard powder and five ounces of flour, and sprinkle the mixture around areas where pets are prone to dig.