Flies are one of the most dangerous enemies of man.They are dangerous because they carry diseases.Flies do not care whether the food they eat is dirty or clean.The food they like best is ofter the dirtiest that can be found.Then they may fly into a house where good clean food is kept and begin to walk all over it and eat it.Soon the good clean food becomes unfit for people to eat.Often a person who is preparing food does not realize that it is unfit for people to eat,so the food is put on the table and eaten.Those who eat such food become dangerously ill.That's why we must get rid of flies.