Why do flies make people hate flies? Why are flies so annoying?

1, flies are dirty and like to stick to people, which makes people feel sick. Flies can spread their own bacteria to people and bring many diseases. They also like to perch on people's mouths and noses with their dirty bodies and wander around people, giving people a feeling of irritability.

I also like to stay beside people's cups. There are so many bacteria in every path he takes. As long as a person takes a cup, he will get sick. Therefore, it is normal for human beings to hate flies as pests.