In his two-line poem, Ogden Nash wrote that “God in his wisdom made the fly and then forgot to tell us why.”

One Sunday a fly was buzzing around our church. I’m sure I was not the only parishioner that found it hard to concentrate on the Pastor’s sermon. With the wave of a hand, the annoying fly went from one person to another.

When the fly landed on the head of an elderly gentleman sitting in front of me, my first instinct was to swat it, however, good common sense — which sometimes leaves me — took over, and I simply chased the fly away. I recall an instance during a nationally televised interview when a fly distracted President Obama.

He caught the fly and swatted it. Later I could not believe the uproar that followed, because he killed the fly. Many suggested he should have let the fly go.

There are many types of flies, and they are usually named according to where they are found. For example, house flies in a house and barn flies in a barn, etc.

The fly, Musca Domestica, has the common name of house fly because in a study done, it was found they made up 99% of all the flies found in our homes. These flies are known to spread a variety of diseases, however they are fastidious groomers. If able to observe one of these flies, you can watch as the fly rubs its feet, draws a leg over each wing and wipes its eyes.

Our common house fly, which often dwells in filth, can carry diseases, particularly stomach and intestinal upsets. In one study done on 378,046 common house flies, entomologists estimated that each fly carried at least 1.9 million bacteria on their bodies.

Flies are a member of a group of insects known as diptera, which means two-winged. All true flies have only one pair of wings, with small, knobbed balancers behind them in place of a second pair. Flies are the only insects that have two wings, with all other insects having four wings.

Flies have always intrigued humans and it has been written that Aristotle enjoyed watching flies, and Shakespeare’s King Lear spoke favorably of them. Egyptian hieroglyphics show that flies tormented the people living along the Nile. In the Bible, flies are referred to as one of the plagues of Moses against the House of Pharaoh.

In Spanish, mosquito means little fly. Although flies are detested, they are beneficial. There are about 16,000 types of flies, including mosquitoes and gnats, in North America and about 80,000 different kinds of flies in the world. Most of these flies do not come into our homes.

The average flight speed of a fly is 4.5 mph. It’s not until autumn’s chill that they invade our homes, becoming groggy and slowing down enough to be closely watched.

Flies have keen eyesight and if you have ever tried to swat a fly, you’ll agree. A fly has hundreds of eyes massed on the sense organs in front of its head. Each eye has 4,000 lenses. These eyes have no eyelids, with which to keep them clean. What we humans do with a blink — on the average of 2,000 times a day — the fly does with its feet.

Flies dine on a host of foods. A liquid is sucked up by a fly as if using a straw. If the food is solid, the fly will either scrape it with its teeth or dissolve the food by regurgitating on it. However some sources say flies do not have teeth but do have a needle-like spike that is thrust into a victim’s skin, injecting a digestive juice that breaks down cell tissue.

While all of this sounds disgusting, flies are an important part of nature’s cleanup crew.

Supposing that two house flies’ mate in the spring, with the female laying 120 eggs that all hatch, and all resulting flies live and breed, the descendants of the original pair would number about five- and one-half quintillion, weighing billions of tons by the end of the summer. The average housefly lives an average of 21 days.

With flies having a wing beat of two hundred times per second, their gigantic wing muscles are easy to study. Through these studies, scientists are trying to understand the human nervous system.

The housefly belongs to the order Musca domestica. Musca is Latin for fly, and domestica, in Latin, means the house. If you want to learn a lot about a housefly, just try catching one. They can walk upside down, zoom through the air at a high rate of speed and then land suddenly and securely in almost any position.

A fly has a quick take off, quick response in turning and excellent vision. It is almost impossible to swat a fly on the first try.

When the weather becomes cooler, flies begin their invasion of our homes. Houseflies are very adaptable creatures and how they spend the winter in one setting will not hold true in another. Flies can live in buildings, such as cow barns, remaining active and breeding all winter long. In our area, most adult flies die from old age or the cold. In the spring, most of the flies that are seen flying around as the days become warmer are houseflies that have emerged from the larvae state.

While working as a wildlife officer we were trained to determine the time of death in decomposing animals by using flies and other insects. We were taught that there are four distinct stages in an average house fly’s life, and these stages can be used to determine the time of death in an animal. The first stage is the egg stage and depending on the size of a female house fly, she can lay up to 500 eggs in a three-to-four-day period on the dead carcass.

The eggs, which are white in color, are usually less than half an inch in size. The second stage is the larvae stage, which is referred to as maggots. Maggots emerge from the eggs within eight to twenty hours of being laid. The maggots will then begin feeding on the dead carcass. The warmer the temperature the faster this occurs. After about four to ten days, the maggots crawl away from the carcass to higher, dryer ground. Here they pupate into the final stage of their life. This process takes about three to six days and is where the maggot encases itself in a reddish-brown skin, where the final stages of development take place.

The last stage is the adult fly, which hatches from this final stage. The fly has an approximate life span of 15 to 30 days. Females can start producing eggs after two days of life and will continue to lay eggs for about a month. Female house flies are usually larger than the males. The adult fly then breaks out of the hard skin, feeds, mates, and starts the cycle all over. A fly is born the size it will always be, never growing during its last stage.

Bill Bower is a retired Pennsylvania Game Commission Wildlife Officer. Read his blog and listen to his podcasts on the outdoors at www.onemaningreen.com.