Remove any standing water from around your home. Mosquitoes can lay thousands of eggs even in a small cup of water. Removing any standing water, even a puddle, helps eliminate a mosquito's breeding ground and places where most of its egg, larvae and pupae stages are carried out.
Apply a mosquito larvicide to areas where standing water cannot be completely eliminated. These chemicals are designed to kill mosquito larvae before they can mature into adults. They usually contain either a bacteria-produced toxin, bacillus thuringiensis israelensis, or the chemical methoprene. Follow all package instructions to prevent harm to plants, humans or animals. The bacillus thuringiensis israelensis may be less effective on pupae since the toxin needs to be ingested and mosquitoes don't eat in the pupa stage.
Add garlic oil to any standing water that can't be removed that is still showing signs of mosquito growth. The sulfur compounds contained in the oil are toxic to both larvae and pupae and should kill off any remaining mosquito life.
Spray mosquito repellent around your yard and use pesticide if mosquitoes continue to be a problem.