Garden snails possess a ribbon-like structure in their mouths called a radula, which is covered in up to fourteen thousand microscopic teeth used to scrape food into their digestive tracts.

A Feeding Tool Built to Wear Out

A snail does not chew with jaws in the familiar sense. It feeds with a radula, a flexible strip that works more like a tiny rasp. Muscles move the strip against food, and its microscopic teeth scrape loose small pieces that can then be swallowed. Depending on the snail, that food might be algae on a rock, soft plant tissue, or other material it can graze from a surface.

The teeth take the brunt of that work. Rather than keeping every tooth sharp indefinitely, the snail continually replaces the ones that scrape at the front. New teeth form farther back, mature, and move forward as the strip advances. The radula is therefore not simply a mouthful of teeth: it is a renewing surface, with fresh working rows arriving from behind.

The Shape of the Teeth Matters

A radula can carry thousands of teeth, but their arrangement and shape vary among snails. Those differences suit the way a species feeds: scraping a film from a surface calls for a different tool from tearing into tougher food. The same basic system can thus serve very different diets without requiring the snail to replace its entire feeding apparatus whenever its teeth wear down.

That renewal is the useful twist: wear is built into the design. Each scrape spends a little of the front edge, while the next row is already on its way to take over.