Blow flies like the smell of rancidity. With all due respect, I apologize for any offence! Quickly check whether there is any dirty garbage in the house, especially whether there is feces, dead animals, etc. in the corners. A long time ago, blowflies suddenly flew into my yard, and I smelled a foul smell. In the afternoon, I discovered a dead rat in the corner after eating rat poison. So quickly find where the flies are flying and clean them up quickly.