Many different products are marketed that claim to repel mosquitoes, and any number of folk remedies are circulating via email and word of mouth. What really works?

The short answer seems to be: DEET. DEET is the common name given to N,N-diethyl-3-methylbenzamide - you can see why a common name was needed. It has been used for decades in skin-applied commercial insect repellents and is effective for hours. The amount of DEET in the repellent should be between ten and thirty percent; higher concentrations can cause adverse reactions. Children under twelve should only wear a ten-percent solution, and under two, you may wish not to use repellent at all.

Many people are searching for a 'natural' solution to repel mosquitos, and there are a number of common plants that have a limited effectiveness. Citronella candles or oil for patio torches is a widely used method of providing friendly outdoor lighting while attempting to repel mosquitos. Studies have shown that people seated near a burning citronella candle suffer fewer bites than people not near the candle, but fewer bites isn't the same as no bites.

Wearing citronella-based 'all-natural' skin-applied repellents can be effective, but the duration of the protection is considerably shorter than that for DEET-based repellents. Repeated applications are necessary if you want to continuously repel mosquitos. Other plants that show some repellent characteristics are cedar, lavender, garlic, cinnamon and peppermint. Some claim that a garlic tablet taken once daily makes the recipient unattractive to mosquitoes, but there is only anecdotal evidence that this works.

Avon's Skin-So-Soft skin moisturizing bath oil enjoys a reputation for providing protection against biting insects. Unfortunately, while it does provide some protection, it is short-lived, less than an hour in laboratory studies.

Bug 'zappers' will remove some of the insect population from the immediate vicinity, but of course can't provide complete protection against all mosquitoes. Some people have built bat houses to encourage bats to move in and dine on any mosquitoes within their range.

The most alarming of recent pest control products is the home mister system, an expensive and potentially dangerous series of chemical release valves that are set around one's home. These periodically produce a mist of chemical insecticides into the air. Like automatic sprinkler systems, the misting system is on a timer and sprays on a predetermined schedule. The mist drifts as the wind takes it, potentially into a neighbor's yard, fishpond or children's playground. The effects of exposure to the chemicals used aren't well known, and the systems kill beneficial insects as well as pests. Their effects on pets and wildlife are also unknown. Unless you can ensure that the mist from your home misting system will not adversely affect yourself, your neighbors, your children or your pets, it is irresponsible to use such a system to repel mosquitos.