Everyone's body chemistry is a little different, and some people are more likely to attract unwanted insect advances than others are.

Mosquitoes can sense your presence from far away. When you breathe out, you emit a plume of carbon dioxide that carries on the breeze, and CO2 also seeps from your skin.

Mosquitoes are attracted to carbon dioxide as well as the warmth and humidity you're giving off, They follow the trail, flying in a zigzag pattern, until they find the source. In addition, they are also attracted to certain chemicals in your sweat. And mosquitoes love a moving target -- it helps them zero in.

Common diseases spread by mosquitoes include:

1. Dengue, a viral infection that causes a high fever, headaches, joint and muscle pain, vomiting, and a rash. Most people get better within a few weeks. In some cases, it can become very severe, even life-threatening.

2. Malaria, a parasitic disease that causes serious symptoms such as high fevers, shaking chills, and flu-like illness. It can be life-threatening, but there are drugs to treat it. Malaria is a major health problem in many tropical and subtropical areas of the world.

3. Chikungunya, a viral infection that causes symptoms such as fever and severe joint pain. The symptoms usually last about a week, but for some, the joint pain may last for months.