An oyster drill, Urosalpinx cinerea, on red sponge in Shark River Inlet in Avon, New Jersey, USA. Human are not the only ones that like to eat oysters. The oyster drill patrols the oyster reef in search of young oysters to eat. In Shark River Inlet, it feeds on blue mussels. The oyster drill has a couple of tools that it uses to get into the hard shell of an oyster. barnacle or mussel. One tool is a chemical that softens the shell. The other tool works like a small file to drill a hole into the shell. The oyster drill will feed upon the soft meat inside. Oyster drills also will feed upon barnacles, mussels, and other hard-shelled animals of the oyster reef.