What does a winkle eat other than crabs?

A "winkle" is a common name for a type of small sea snail, usually referring to the common periwinkle (Littorina littorea).

Periwinkles are herbivores and their diet primarily consists of algae, especially the types that grow on rocks and seaweed.

They may also scavenge on dead organisms and occasionally eat small invertebrates, but crabs are not part of their usual diet.