Some people seem to attract mosquitoes more readily than others, and experts say the attraction has mostly to do with the amount of carbon dioxide that comes through a person's skin.
"It's not blood type," said Dr. Jonathan Day, a medical entomologist at the University of Florida. Day has spent 20 years studying diseases that are transmitted by insects.
"It's not what you eat or what you don't eat," he said. "It has to do with the amount of carbon dioxide you produce."
The body emits carbon dioxide through the breath and through the skin. Mosquitoes are attracted to the carbon dioxide that comes through the skin, said Day. The more you produce, the more mosquitoes are drawn to you.
That's bad news for active people. The more you move around, the more carbon dioxide you produce. Also, when the muscles work they produce a waste product called lactic acid. This comes through the skin and attracts mosquitoes, Day said.
Other factors that draw the bugs in are body temperature and size. The larger and warmer you are, the more likely you are to attract mosquitoes, Day said.
Dark colors also make you an easy target.
"Mosquitoes tend to fly pretty close to the ground," Day said. "They look at you against the horizon, so dark colors stand out." The best color to wear is yellow, Day said.
Alligator trapper Tony Hunter grew up hunting in the Florida Everglades, where the mosquitoes would surround the boats in a faint black fog.
"We tried everything," he said, "eating garlic and Vitamin B1, but personally I never really noticed a difference. I think we just gave them a little more flavor in their meal."
The worst, he said, was when he and his friends heard parsley might help. They sprinkled everything they ate with the flakes. "Nasty stuff," he said. And it didn't work.
Dr. Kenneth Boch of the Center for Progressive Medicine in Albany uses nutritional supplements and herbs in his practice, but he hasn't found anything that works well to repel mosquitoes.
Some people have luck with high doses of vitamin B1 (100 milligrams, two or three times a day), he said.
Chemical insect repellent is the best thing to keep mosquitoes away, according to both Hunter and Day. Both said repellents with the ingredient DEET work well.