What are flies doing rubbing their hands?

Flies rub their hands for the following reasons:

1, keep it clean. Flies are so dirty, do you want to keep them clean? It's true. When flies fly everywhere, they will stick a lot of dirty things on their bodies. If these things are not removed, flies will feel a little heavy when flying, which will affect their flight.

2. This is related to the taste system of flies. If we need to know the taste of a certain food, our taste system is on the tongue.

3, in order to spread * * * bacteria. Flies often crawl around in dirty places like garbage dumps and sewers, and their feet rub back and forth on dirty things.