m4dd0g said:
Why do mossies always go after me?
There is a bunch of reasons why mosquitos will seek out specific people over others.
* Dark Clothing
Many mosquitoes use vision to locate hosts from a distance. Dark clothes and foliage are initial attractants.
* Carbon Dioxide
You give off more carbon dioxide when you are hot or have been exercising. A burning candle or other fire is another source of carbon dioxide.
* Lactic Acid
You release more lactic acid when you have been exercising or after eating certain foods (e.g., salty foods, high-potassium foods).
* Floral or Fruity Fragrances
In addition to perfumes, hair products, and scented sunscreens, watch for the subtle floral fragrance from fabric softeners and dryer sheets.
* Skin Temperature
The exact temperature depends on the type of mosquito. Many mosquitoes are attracted to the slightly cooler temperatures of the extremities.
* Moisture
Mosquitoes are attracted by perspiration because of the chemicals it contains and also because it increases the humidity around your body. Even small amounts of water (e.g., moist plants or mud puddles) will draw mosquitoes. Standing water also allows mosquitoes to reproduce.
Taken from
here
So as you can see, it's mostly because you smell.
m4dd0g said:
And where do flies go in winter?
They die.
Depending on the species of fly and the temperature, they have an average lifespan of anywhere between one week and 1-2 months
Basically winter is just too cold and wet for the flies to handle. When it gets to lower than 12 degrees Bush Flies for instance can't fly at all. They need the heat to be able to get up into the air, and if it's only
just warm enough, the wind chill factor while flying will actually slow them down and can make them drop out of the air again.
Once it starts to warm up again, the warm wind from the northern states actually blows new flies down south to bother us again.