Spiders can be an annoying pest around homes. In rare cases the arachnids are poisonous, but they are most famous for their webs that leave a home looking dirty and uncared for. Many people work hard to kill or repel spiders, even though most are beneficial because they capture and kill other bugs.
For decades people have used citronella oil to repel mosquitoes. It seems to repel a wide variety of pests, including spiders. As a rule, don't use citronella candles. Spray a mixture of a quart of water, five drops of citronella oil and a teaspoon of lemon dish soap on areas of the home where spiders are a problem.
Tea Tree Oil and Neem Oil
Many people use tea tree oil and neem oil in the treatment of skin conditions of both humans and pets. These oils also seem to repel spiders. Mix a quart of water with one ounce of neem oil and five drops of tea tree oil and two teaspoons of dish soap. Spray the mixture on areas where spiders appear. Buy tea tree oil and neem oil at health food stores.
According to the North Dakota State University Extension Service, a mixture of oil of wintergreen, mineral oil and rosemary oil makes one of many combinations effective for killing spiders, The mixture is available in a commercial formula. The extension service lists brushing away spider webs and vacuuming up spiders, eggs and webs as other ways to eliminate spiders from homes.
Chemical Insecticides and Glue Traps
Several insecticides effectively kill spiders. Spray these on any surface where spiders congregate. There are also glue traps, with flat sticky surfaces that entrap spiders and kill them, useful where chemical insecticides are not an option. Either method kills existing spiders but does not repel future intruders.
Spiders often congregate around homes and under porches and eaves. They sometimes find their way indoors through cracks in the siding. Removing spiders, webs and egg sacks that you find on the outside of the house limits the number of spiders that can enter the house, reducing the need to repel them in the future.