Absolutely. If nothing triggers their feeding instinct, like the smell of body fluids, blood, decay, or stress chemicals, or something that smells like something they've eaten before, they would starve to death. Even then, some species are probably much less capable of killing their own prey, and couldn't do so even if they realized the food was right beside them. Other species, like the large Nassarius arcularius, are fully capable of killing lots of different animals, but may only do it when exposed to the correct stimuli.
Cheers,
Don