Flesh fly feeding. Macrophotograph of a gray flesh fly Sarcophaga carnaria, feeding on sugar. The tube-like proboscis mouthpart of the fly is seen; it is designed like a suction tube. Positioned on the side of the head are two large compound eyes (red) made up of many facets (ommatidia) which together are sensitive in detecting movement. Hairs or setae cover the fly's head, legs, and tip of the proboscis, and may be used for touch. Sarcophaga carnaria is closely related to the bluebottle fly and like them is a domestic pest.