Bleach has a multitude of uses. It is classified as a pesticide and fungicide due to its ability to kill bacterial cells. Bleach is also able to whiten whites, discolour coloured products and even neutralise anthrax. These effects are caused by the acid in bleach, which eats away everything in its path. Bleach's acidity also gives it the ability to kill household pests, including spiders. It is, however, not a registered insecticide because of its harmful side effects on both humans and on the surfaces it is sprayed on, so caution is advised when using it to kill spiders.
Mix one part bleach with three parts water in a spray bottle.
Spray the mixture directly on spiders at a 15 to 25 cm (6 to 10 inch) range. Use however much is needed to kill the spider. The exact amount depends on the spider's size.
Sweep up the dead spider and throw it away. Wipe the bleach from the surface to avoid any bleaching effects.
Spray the bleach mixture on areas where spiders are known to nest, hide or enter the house every week until the winter season to serve as a repellent.
Be careful how close you stand when spraying bleach. Bleach can damage your eyes and skin if you come in contact with it for long periods or in large quantities. Watch what you bleach. Bleach can discolour walls and floors.