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You're outside flipping some burgers, getting supper ready for your family, but then you realize you have already become supper for someone else - the mosquitoes.

Why is it that some people get bitten all the time and others are spared? Is it just your imagination?

It isn't. Mosquitoes do have blood-sucking preferences. In fact, one in 10 people are highly attractive to mosquitoes.

First of all, you should know that not all mosquitoes suck blood. Only the females do because they need human blood to develop fertile eggs. Female mosquitoes have a long proboscis, which is a long, thin, needle-like syringe located at the mouth. They use this needle to pierce their victims' skin and drink their blood until their abdomens are full. When feeding, a mosquito can drink anywhere from 0.001 to .01 milliliters of blood.

When a mosquito bites, she injects some saliva into the wound to prevent your blood from clotting. After she is finished, some of her saliva remains and proteins in it evoke an immune response from your body. This is why the area where you were bitten swells and you itch.

But why are some people more appetizing to mosquitoes than others?

Genetics account for 85 per cent of our susceptibility to mosquito bites, so if your parents were always bothered by mosquitoes there is a good chance you will be too.

There are certain elements of our body chemistry that, when found in high concentrations on the skin, attract mosquitoes. People with high concentrations of steroids or cholesterol, for example, on their skin's surface are a magnet for mosquitoes. This doesn't necessarily mean that someone with high cholesterol is more likely to be bitten, it just means that someone who is more efficient at processing cholesterol will have more by-products on their skin's surface which attracts mosquitoes.

Other things that catch the attention of mosquitoes are body odour, uric acid and lactic acid. These things can trigger a mosquito's sense of smell, luring them toward unsuspecting victims. Mosquitoes can actually smell their dinner from up to 50 meters away.

Carbon dioxide is a very strong attractant for mosquitoes, which is why they often prefer feasting on adults instead of small children, because larger people tend to give off more carbon dioxide. Pregnant women are also a favourite target because they produce a greater-than-normal amount of exhaled carbon dioxide.

So what are mosquitoes equipped with to sense all of these things from their prey?

Mosquitoes have a set of sensors designed to track their victims. The first are chemical sensors which lets them tell which mammals and birds are giving off higher amounts of gases such as carbon dioxide and lactic acid. Insect repellents containing the active ingredient DEET work by confusing the chemical receptors of the mosquito so that they can't zero in on the source of the carbon dioxide.

Mosquitoes also have visual sensors which allow mosquitoes to see moving targets and contrasting colours. The final sensors are heat sensors so they can find warm-blooded targets very easily when they are close enough.

Some mosquito myths:

It has been found in controlled laboratory studies that the ingestion of garlic or vitamin B12 does not repel mosquitoes. Conversely, eating bananas does not attract the little pests. However, people wearing perfume or drinking beer have been known to be more attractive to mosquitoes.

So if you want to try to fly under the mosquito radar at your next outdoor gathering, park yourself in a chaise lounge rather than playing Frisbee on the lawn. This way, the mosquitoes will hopefully be attracted to the moving targets who are releasing all of the carbon dioxide from breathing heavily and sweating all of the lactic acid.

Karla Gimby is the communications director at Science East. The Science East column appears every fourth Wednesday. Please send comments to letters@dailygleaner.com.