Drain flies become an irritation when they lay their eggs in old food particles, slimy grease, sludge, and other items that buildup in a drain. That's why it's imperative to mail out several mailings, nine, ten, twelve a year or a good deal. https://Wiki.Insidertoday.org/index.php/Reasons_For_Hiring_A_Pest_Control_Company_For_Your_Treatment_Of_Domestic_Pests