The fly goes through his life cycle in four different stages, He begins life as an egg. Then he hatches into a hungry maggot. Next he goes to sleep for a spell as a pupa. When he wakes up, he breaks out from his hard pupa case as a fully grown, winged fly,
It takes warmth for the maggot to hatch from the egg. So, when the weather turns cool in the fall, the flies still in the egg stage do not hatch. All the grown flies, or most of them, perish in the cool months. But the little white eggs survive the winter, waiting for the warm breath of spring. Then they hatch into grubby little maggots.
There is only one goo.d thing we can say about flies. They provide food for our friends the birds. All the other news about these pesky insects is bad. True, they are dainty‑looking creatures and, when you watch one carefully washing his body you might suppose he is clean. But this is not so.
Most flies think they have a right to land on anything they choose. One of their favorite landing fields is an open garbage can. Decaying matter is always full of microbes and many of these microbes carry disease. When Mr. Fly lands in the garbage can seeking food all kinds of microbes cling to his sticky feet.
No matter how much the fly seems to clean himself, these microbes are not removed. Off he zooms, and his next landing field may be your kitchen table. If there is food around, he is sure to seek it out. The microbes he collected from the garbage can may end up on a piece of your bread or butter. So yes, indeed, these free‑flying creatures are very dangerous to have around.. Let's screen our doors and windows and, most important, keep a tight lid on the outdoor garbage can.
Another troublesome thing about flies is the way they multiply, The first eggs to hatch in the spring are fully grown in about a week. A mother fly lays about 500 eggs. In a week, these eggs may be fully grown flies and, if none of them die, all the mamas will lay 500 eggs apiece. Suppose all of these flies lived and. this rate of multiplication went on all summer. By fall, that one mama fly would have about 200 quintillion descendants. That figure is 200 followed by 18 zeros. altogether, they would weigh almost five million, million tons.
Luckily for us there are hungry birds, bats, snakes, frogs and a host of other creatures just waiting to eat up that tremendous fly crop. Even so, a few mother flies manage to hide their eggs so that they survive the winter. And a very few grown flies hide in warm nooks and zoom forth on warm winter days. But most of the grownups perish with the first frost,