Originally Posted by J-Fight
Is it true every time a fly lands on your food it pukes and licks it back up ? lol
just an old tale from growing up...
flies taste with their feet, more specifically, with the hairs on their feet (in addition to the hairs near their mouth parts). when they land on something that tastes like food to them (e.g. your fried chicken, or your dog's crap in the back yard), they extend their mouth parts and regurgitate digestive juices on it. flies have no way to chew food, so they essentially vomit stomach acid on food and then suck it up after it has dissolved some of the food.
their proclivity for walking alternatively on offal and stuff you eat, as well as their constant pooping are why even non-biting flies are so good at spreading disease.