The mouth of the snail has a grater (radula) used for scraping and grinding food.

An excerpt from the article 19 facts about snails

It is a cartilaginous structure covered with a large number of tiny chitin teeth. It is set in motion by muscles. It occurs in both herbivorous and carnivorous snails. The structure of the radula does not necessarily have to be related to the snail species and is often determined by diet. The cloves may take on a pointed shape when the snail feeds on algal tissue, and when it feeds on epiphytes (plants growing on other plants), the cloves are usually blunt-ended.