Nutrition

The above picture is of a snail eating (this is not a Fossaria obrussa).

What do snails eat?
Snails have shells made up of calcium carbonate so therefore they need to eat a diet high in calcium to keep their shell strong so they stay protected. But this is only until their shell is made, once it is done growing they no longer need to consume calcium(Perez 2011). Most snails are herbivorous (eating only plants) or omnivorous (eating plants and other animals, they can also be cannibalistic eating other snails and their shells as well). I think of them as the goats of the gastropod world... because they sample almost anything as they crawl on their merry way. Another requirement is a moist environment to avoid evaporation, ensure a strong shell, and to produce mucus which aid's them in moving from  place to place (mucus is made up of water)  ( Carnegie Natural History of Life).
How do they find their food?
Snails have chemoreceptor's on their tentacles (ommatophores) and are similar to the nose of a mammal. Freshwater snails like the Fossaria obrussa have eyes at the base of the first set of tentacles. Most land snails carry their eyes at the tips of the first set of tentacles (Animal Diversity Web).
They make noise when they are eating?
Yes, a snail does make noise when they are eating! What you are hearing is the radula. This is how they break apart their food, they scrape at it and then it  goes to the digestive tract. The undigested food is excreted through the anal pore(Animal Diversity Web).


Their diet consists of:
 Plants and plant material ( live and decaying)
 Fungi
 Algae (other soft material)
 Animal waste and other material
 Other snails, their shells and carcasses
 Organic and inorganic soil
 Rock particles


The above picture is of an actual Fossaria obrussa .