In New England, especially during the warmer summer months, house flies (musca domestica) are perennial pests that constantly buzz about your premises looking for an opportunity to land on your food.
In the wild, flies play an important role in the eco-system. They aid in the decomposition of decaying plant and animal matter, pollinate plants, and provide food for a host of other animals. In your house, however, they are just pests.
We could probably list a hundred reasons why house flies should be kept as far as possible away from human food, and there are over a dozen reasons given below if you break them up minutely. But we can conveniently organize our no-fly-on-food motivations into three general categories:
1. Flies can transmit diseases and parasites
Given where flies spend most of their time and the unsanitary types of food they typically eat, it is not surprising to find that they carry numerous pathogens and parasites.
In fact, scientists tell us that house flies are twice as likely to spread disease as are cockroaches, despite the fact that most people’s aversion to the latter insect is far stronger.
What kinds of disease do flies carry? Cholera, typhoid fever, salmonella, worms, and dysentery are on the list. But the truth is, you never know because any germ that lurks in a poop pile, on a rotting carcass, or in some other revolting location can get on or into flies’ bodies and then onto your food.
2. You don’t want to eat fly body fluids or substances stuck on flies’ bodies
Flies have no teeth, and thus, they can never bite you like a mosquito can. Good news? Not necessarily — here’s why.
Without teeth, flies must resort to spitting on their food and then gulping it down as the saliva softens it. They may also spit up food again after taking it into their mouth for a time. Fly feces and urine may also be left on food flies feast on.
Finally, feces or rotting material from dead plants or animals will attach itself to flies’ hairy legs and all over the fly’s body. That is the method by which bees and butterflies pollinate plants, and this contact-transfer method works in a less appealing way in this instance.
3. Flies lay their eggs in food they land on
Given enough time on top of your food, flies may take the opportunity to lay their eggs in it. You will not be able to see the eggs, but they are there.
And within a few days’ time, maggots will appear in the food. That’s both a gross thing to see and total waste of the food. In a restaurant setting, it could mean failing a health inspection or losing customers.
Should I toss any food a fly lands on for even a second?
Some people become extra-cautious and throw out food if they see a fly land on it for even a second. Health experts tell us that it would likely take more time than that for a fly to dangerously contaminate food.
Nonetheless, realizing what flies do to food does tend to make one want to immediately react in this way.
Fly control strategies
The first thing you can do to curb house fly populations is to simply install/repair screens in doors and windows, take the garbage out often, and keep your house spic and span.
Fly paper, fly lights, and other fly traps can also help with fly control. For the most serious fly problems, you may need to use special insecticides and should contact a professional pest removal service.