Fruit flies are attracted to ripened or fermenting fruits and vegetables. Fruit flies are common in homes, restaurants, supermarkets and wherever else food is allowed to rot and ferment. But they also will breed in drains, empty bottles and cans, trash containers, mops and cleaning rags. They have the potential to contaminate food with bacteria and other disease-producing organisms.
(From University of Kentucky)
House flies taste with their feet, which are 10 million times more sensitive to sugar than the human tongue. They can only eat liquids but turn solids into a liquid through spitting or vomiting on it. They eat any wet or decaying matter, but are particularly attracted to pet waste. They breed in garbage cans, compost heaps and pet areas. These insects have been known to carry over 100 different kinds of disease causing germs.
(From National Pest Management Association’s www.pestworldforkids.com)