They are known to frequently eat large whelks (Buccinum), cockles (Polynices, Chrysodomus and Sipho), sea clams (Mactra), large hermit crabs, starfish, sea urchins and green crabs (Carcinus maenas).
The hermit crab Pagurus hirsutiusculus (Dana, 1851) can be found in empty shells of Baer's Buccinum.