Why do flies rub their legs together?

When you see a fly rubbing its legs together, it is cleaning itself, and scraping off some of the material that has gathered there. A fly is an insect with a pair of well- developed wings. The common housefly is one of the beat-known kinds of flies; a scavenger, it does not bite living animals but is dangerous because it carries bacteria that cause many serious disease such as typhoid fever, cholera and dysentery. The housefly feeds by depositing a drop of digestive liquid on its food, which may be food that has been left uncovered. Disease can also be transmitted on the fly's sticky foot pads and hairy body.