Ok, how worried should I be. I have tried to be very careful but these flies are awful. I have a trap out and am catching them but they are still in my house. Last night I was working on some grapes, smashing and juicing and working with a fan on trying to keep flies away. Put juice in primary covered with a towel and sheet after adding campden tabs. This morning checking temp and sg. and notice a fruit fly floating in must! Am I in trouble? Please any advice? thanks