Bleach, vegetable oil and garlic are some common household items that can kill mosquitoes, as well as traps made from two-liter soda bottles and brown paper bags that are baited with sugar and active yeast. Chlorox bleach is rated by the Environmental Protection Agency as an insecticide.
Bleach and vegetable oil are best used to kill mosquito larvae in standing water around the house, such as bird baths, fountains and landscaping ponds. One-tablespoon of bleach for each 50 gallons of water is sufficiently toxic, while enough vegetable oil to cover the top of the water and prevent the baby mosquitoes from surfacing for air works well too.
Traps built using sugar and active yeast are very effective for adult mosquitoes because the insects are lured inside of the traps by the carbon dioxide generated by the bait.