Mosquito Barrier is a very strong liquid garlic made from very potent garlic cloves. The garlic used in Mosquito Barrier is a very powerful variety which is much more potent than the garlic found in grocery stores. Garlic has a natural sulfur which repels insects, including mosquitoes, ticks, fleas and even black flies. Spraying garlic to keep insects away is not something new, farmers and master gardeners have been doing it for many generations. Since mosquitoes are soft-bodied insects the garlic juice can be very toxic to them in increased concentrations. The juice does not harm humans or pets or plants, but to mosquitoes it can be deadly. The odor of it chases them out of the area and they stay away - for as long as they can detect the odor. While the odor of sprayed garlic juice becomes undetectable to humans within minutes, the mosquitoes will still detect it. Mosquitoes have extremely sensitive odor sensing antennae - as high as 10,000 times better than humans. They can detect the garlic extract for much longer periods of time and will stay away from the sprayed area for up to a month and more. If the mosquitoes aren't in your yard, they can't get into your house. Additionally, Mosquito Barrier, when mixed with soybean oil (available at your local grocery store) plus the water, coats any standing water in the area with a very thin film of natural oil, including some garlic oil which is present in the garlic juice. This oil suffocates the mosquito larvae which are developing in any standing water. Mosquito Barrier, unlike harmful chemicals, doesn't kill bees or butterflies and is completely safe for children, fish, birds, dogs, cats and other pets. Generally, four applications are enough for the entire mosquito and tick season. Even in the heaviest of infestations the gallon size is almost always enough for the entire year for most homes - including areas where the mosquito is the state bird.