We all know the common fly too well. At certain times in the year, especially in the hot weather, flies are a perfect nuisance. They come into our houses in great numbers, especially at meal-times, and the buzz about and tickle us by crawling over our faces. We flip them away and kill a few, but still, they come and worry us. For flies seem to have no fear, and the only way to stop their teasing is to kill them.
But flies are not only troublesome; they are really dangerous. We have noticed how flies always come in swarms when there is any food about, especially fruit and meat. They come to food, partly to eat, but partly to lay their eggs. When they lay their eggs in meat, the meat very soon goes bad. The reason for this is that these eggs hatch out in a few hours into little worms or maggots, which feed upon the meat. And then the meat is bad, and cannot be eaten.
But what is worse is that the house-fly can give us certain kinds of diseases. Flies not only eat clean things like fruit, but they feed upon all kinds of rotten stuff like manure, rotting vegetables, and filthy stuff in the drains. Then they come and sit on the sweet-meat and fruit and cakes in the bazaar, and crawl over them with their dirty legs, and leave all kinds of diseases behind them on the food that we eat.
A poet once wrote a poem to a fly that was drinking out of his cup. It began:
“Busy, curious, thirsty fly!
Gently drink, and drink as I;
Freely welcome to my cup,
Couldst thou sip, and sip it up.”
But he did not know how dirty and dangerous flies are. If he had known, he would have driven the fly away, and not welcomed it in a poem.