House fly, magnified.
The hairs on its body and legs catch
dirt and disease germs.
209. Foul air.—If we live in a closed room, the air soon becomes foul and dusty, and is likely to have disease germs in it. Foul air is one of the greatest of the causes of sickness. We should change the air of a room often so as to keep it fresh and free from dust and disease germs (pp. [65]–[67]).
210. House flies.—House flies come from garbage heaps and filth of all sorts. So they carry disease germs on their bodies. They light on our food and on our faces, and so they often make us sick. They are often the cause of typhoid fever, stomach aches, and stomach sickness in babies.
Life history of house flies.
Flies are hatched in manure piles and garbage heaps. At first they look like white worms, and are called maggots. Every maggot is a young fly. We can get rid of flies by cleaning up every garbage heap and manure pile.
