Flies are one of the most commonly encountered pests around the globe. Nuisance pests in most situations, flies can also represent a serious health threat as they are capable of transmitting numerous communicable diseases. Flies vary greatly in size. Tabanids can be up to 1 inch long, while drosophilid flies are only 1/8 – inch long. Flies are identified by only having one pair of wings. Their hind wings are shrunken and modified into small, knobbed structures called halters, which function as stabilizers during flight. Flies undergo complete metamorphosis: egg, larvae, pupae and adult. Most flies associate themselves with decaying organic material.