Flies are often first on the scene of a dead body

The first type of insect to arrive at a dead body is usually a blowfly (Calliphoridae), attracted by body fluids and gases. It lays its eggs within two days after death, so its stage of development – egg, larval stages, prepupal or pupal stage, adulthood – will suggest how long the corpse has been lying undetected. Ambient conditions affect both how soon after death the blowflies arrive and how quickly the maggots develop. The female fly will lay her eggs in the moist locations of the body; eyes, ears, nose and mouth. No info about the dead man in the image.