QUESTION: Is it normal to have flies in compost?
ANSWER: Vinegar flies are common in compost piles, as they are attracted to fermenting or rotting fruit. As long as you avoid adding meat or bones to your compost pile, you won’t attract any typical houseflies. If you have a problem with flies in your compost, the best way to discourage them from staying in your pile is to turn and mix the contents of your pile daily.
Continue turning the pile daily until the larvae die and the flies move on to calmer environments. Once the flies have abandoned your pile, reduce turning to once or twice per week.