Destroying fly is beating me

Find out what's breeding them first. House flies point to bins or food waste. Little ones round the fruit bowl are fruit flies - a jar of cider vinegar with a drop of dish soap, covered in cling film with a few holes, sorts those. Tiny ones by the plants are fungus gnats and the soil is too wet. For house flies: bins lidded and cleaned, screens on the windows, and sticky traps by the windows.