Do read this description – these are really cool insects.
It lays its eggs in, and its larvae consume, raw flesh (particularly that of dead animals) and fungi. The larvae and adults also consume fly larvae and the larvae of other carrion beetles that compete for the same food sources as its larvae.
From spring through fall, during daylight, a few hours after flies begin arriving at a carcass, the adult beetles will arrive as well. They immediately begin eating the already hatching fly larvae, mating, and laying their own eggs. As long as the carcass lasts, the adults will remain eating competitors to give their own larvae a chance to eat and grow. Upon hatching from the eggs, the larvae will eat both the carcass and other larvae that are within it. Eventually the larvae will fall to the ground, dig into the dirt, and pupate. Overwintering is done by adults.
Now the fascinating bit – The beetle is known to engage in mutualistic phoresis with mites of the genus Poecilochirus. Upon arrival at a carcass, these mites drop from the beetle and begin eating the eggs and larvae of the flies that preceded the beetles (and continue to lay more eggs even as the beetles are active). They will eventually return to the adults and be transported to the next carcass. Some of their young will hitch a ride with the beetles’ young upon their emergence from the pupal stage.